Final Report Summary - COEUS-TITAN (INNOVATIVE SMART COMPOSITE MOULDS FOR COST-EFFECTIVE MANUFACTURING OF PLASTIC AND COMPOSITE COMPONENTS)
Executive Summary:
COEUS-TITAN aims to develop innovative, robust and easy to heat composite moulds (both closed and open), through addressing all those issues that currently prevent composite tooling from being viable alternative for the industrial production of plastic and composite parts across a wide range of manufacturing routes.
Most important Innovations are:
i. Embedded heating elements, based on the carbon reinforcement of the mould, close to the mould-part interface demanding less energy.
ii. Incorporation of flow, temperature and cure sensors that will enable full automatic control of the process.
iii. Layout of a cooling system consisting of a conformal (following the contour of the part) tubing network.
iv. Use of piezoceramic film actuators which will induce micro-vibrations and thus assist resin flow inside the cavity. Such actuators on the edges can be used for demoulding and thus reducing tool complexity and demoulding time.
Integration of these functionalities into a single “smart” mould is anticipated to impart a significant advancement of the composite and plastics manufacturing industry.The aspects of this innovative tooling concept pursued and developed in the course of the project are listed below:
A low cost, thermally insulated GRP/CFRP composite tooling base acting as the structural reinforcement of the mould cavity.
A mould cavity constructed by a doped laminated, thermally conductive thermoset composite, incorporating the following systems:
A heating system comprised of the carbon fibre reinforcements situated beneath the mould surface among a number of high thermal conductivity nano-doped layers that facilitate uniform heating. The heating system is also a load bearing part of the mould.
A conformal cooling system comprised of a conformal network of channels that circulate a heat transfer fluid.
Low friction, high wear-resistant surface layers, implemented either by coating or by doping out of resins with SiC nano-fillers
Piezo-electric actuators that induce micro-vibrations assisting resin flow.
A monitoring system comprising of embedded flow, temperature and curing sensors, which supply data to a central management unit that controls process parameters.
A set of analysis tools for tooling design promoting a distributed engineering approach:
Heat management and simulation of the heating-cooling procedures
Structural and thermal optimisation analysis
Resin flow simulation and cavity filling optimisation
Process parameter optimisation
Sensing and control system design
Coupled model for the full system simulation and optimisation
A techno-economical model for the selection of the production process and the appropriate level of tooling functionality on the basis of optimum production cost.
Project Context and Objectives:
Definition of functional specifications
[OBJ-1] Development of “smart” tooling materials database
• Almost every aspect of the innovations proposed in the project relies on material technology. It is therefore necessary to obtain a database of the candidate materials to be utilised for the smart tooling concept in the course of the project.
[OBJ-2] A detailed exploitation plan for the application of “smart” tooling concept to plastics and composites manufacturing
• First, to gather the state-of-the-art in key manufacturing methods currently used for composites and plastics. Identify the use of composite tooling at high end manufacturing processes and define the extent of application for the smart tooling concept (heating through the carbon reinforcement of CFRP's, modification of surface properties through nano-doping, novel coatings, integrated sensors and actuators).
• Secondly, consolidate the beneficiaries plans in using the smart tooling concept will be further analysed and the specific actions of the beneficiaries for the exploitation of the COEUS-TITAN technology will be defined.
[OBJ-3] Functional specifications for “smart” tooling technologies implementation
• The aim of this task is to identify the data required in order to design a tooling for either an open or closed mould process. Existing designs of tools and dies for typical mass production parts and high-tech low production volume parts (e.g. aeronautical) will be examined in terms of their specifications. The definition of the tooling for the application case studies (on RTM and pultrusion) will also be made here, along with the definition of the simpler experimental tooling to be considered for the pilot scale study. Based on the information gathered the design specifications (heating/cooling system, sensing/actuation and surface configuration) to be satisfied by the proposed development will be analysed.
Heat management technology
[OBJ-4] To fully investigate the capabilities of available heating elements and calibrate their use -Modelling, testing, calibration and optimisation of integral heat element configurations for tooling heating systems
• Heat a composite CFRP structure using the carbon fibres as resistance heating elements.
• Detailed evaluation of the different heating element configurations and the selection of the most convenient solution to be applied in the course of the project
• Development of numerical analysis models for the simulation of the heating system operation will be performed.
• Electro-thermal analysis models able to predict the temperature field over the heating element, given the electrical circuit characteristics
[OBJ-5] To determine the parameters of the cooling system operation - Modelling, testing and optimisation of tooling cooling systems
• Investigate a system embedded into the tooling, comprising of a tubing network that will circulate a cooling fluid. The main issue that must be dealt with is possible heat losses from the heating elements due to heat conduction.
• Development of numerical analysis models for the simulation of the cooling system operation
[OBJ-6] To optimise the thermal properties of the mould cavity materials - Enhancement of tooling materials thermal properties through matrix nano-doping
Smart tooling surface development
[OBJ-7] Definition of tooling surface materials and processes - Selection of the materials and manufacturing route for the preparation of the part prototypes that will be the basis for the building up of the “smart” tools
• Employ state of the art technologies and the best practices for preparing the master model surface, choosing the right materials and applying polymer surface resins. Tooling block materials are available in different densities and with different properties. A tooling block material needs to be machined to create a physical model to be used for mould building. The surface of this model will be copied by the epoxy gelcoat and used to create the mould surface. This is why it is very important to decide on the surface requirements at an early stage.
[OBJ-8] Study and develop manufacturing solutions in respect to the optimisation of the tooling surface quality and durability
• These solutions aim to enhance the tribological properties using the following two approaches:
- Doping of the surface layers with nanofillers
- Application of wear resistant coatings
[OBJ-9] Development of repair techniques for “smart” tooling surfaces
• The selected tool surface configurations will be evaluated in terms of repairability. The worn specimens will be repaired either by standard composite repair techniques in the case of the doped gel-coat configuration or by re-application of the coating.
Sensor / Actuator Technology
[OBJ-10] Adaptation and testing of integrated flow and reaction sensing
• Development of dielectric flow and reaction (cure) monitoring sensors as well as DAQs and mountings embedded into the “smart” tooling. Several small mould mock-up specimens will be fabricated with integrated capacitive elements and their wiring. Ultrasound sensors will also be investigated.
[OBJ-11] Development of temperature sensing in “smart” tooling through the use of integrated thin film technology
• Embedding of thin films in resins under the surface layer of the smart mould construction as temperature sensors
[OBJ-12]Development and testing of the tooling temperature control system
• Supply data to a central management unit that controls process parameters through the use of the embedded monitoring system comprising of embedded flow, temperature and curing sensors. These measurements will form the input to the data acquisition boards.
- The output of the system (through the computer’s D/A interface) will drive the temperature controllers of the heating system.
[OBJ-13] Development of in-tool piezo-electric actuation system – De-moulding function
• Introduce piezoelectric actuators to “automate” the de-moulding process. To accomplish this, the use of patch- actuators will be considered. Patch-Actuators are composed of flat piezo-ceramic plates (0.1 to 0.5 mm) cased inside a ductile polymer film. By applying a voltage to these patches, they generate a deformation of the ceramic which introduces a shear force into the structure.
Software framework for smart tooling design
[OBJ-14] Review of commercially available software for CAD/CAM/CAE, which implement modules specific for the design and simulation of composites manufacturing processes
• Capabilities of simulation
• Input/output file formats
• Interfaces with other more generic CAE tools
• Complementarity of capabilities
• Accuracy
• Usability
• File interfaces & Capacity for interoperability
[OBJ-15] Incorporation of models for flow, thermal, structural and process control
• According to the requirements and capabilities of the process simulation software, the “peripheral” models will be arranged, in terms of data content and format. During a moulding process (either open or closed mould), three stages/processes will be investigated:
1. Mould / tool preheating
2. Filling process
3. Curing /cooling
[OBJ-16] Development of automation functionalities for the smart tooling design software framework
• The overall outcome intended is to configure the design framework in such a way that it will require just the CAD file of the product, material details, time and cost constraints and any other specifications in order to produce (with minimal user intervention/manipulation) the mould design and the full set of process control parameters. This eventually will lead to a user-defined Integrated Design Environment.
[OBJ-17] Implementation and interfacing for techno- economical models
• The implementation of the developed techno-economical models in the software framework as a separate module. Their function will be to estimate the total cost of a part's production depending on the design features and the components included in the mould construction.
Smart tooling technology integration to pilot scale
[OBJ-18] Design of tooling cavity for pilot scale implementation
• The starting point will be the design of the tooling cavity that will include the surface layers, the heating elements and the cooling system. The design aspects to be considered for the manufacturing of the tooling cavity should be able to address:
- Use of a high Tg resin or polymer
- Doping of the resin with nano-sized particles
- The setup of the heating elements
- The incorporation of the cooling system
[OBJ-19] Design a structure that will support the tooling cavity during the high pressure loadings of the RTM and pultrusion processes
[OBJ-20] Integration study of heating/cooling systems
• Although the heating elements are essentially the carbon fibres, the realisation of the heating system requires a set of auxiliary components that need to be introduced into the tooling structure. These are the electrodes for the connection to the power source and the wiring of the circuit.
• The integration of the cooling system, depending on the form selected will also bear upon the manufacturing procedure. The goal of this task is to provide techniques to combine the fabrication procedure for the tooling cavity with the placement of the components of the cooling system.
[OBJ-21] Integration study of sensing/actuation systems
• The first is to embed fittings for the attachment of the sensors during the cavity lay-up. The second is to similarly embed cured resin “plugs”, through the thickness of the structure. Drilling through these plugs will enable fitting of the sensors without compromising the fibres. The acoustic sensors, if selected for application, will pose no significant problem as they will be fitted in the mould base, just under the cavity layers.
• The patch-actuators are in fact tailored to be laminated inside a composite structure; therefore their integration in the mould is a trivial task. The accommodation of the required wiring for all active components (sensors/actuators) will also be detailed in this task.
[OBJ-22] Manufacturing of pilot scale tooling and assembly
• The work of this task is the actual fabrication of the pilot scale tooling given the design and instructions derived thus far. During the manufacturing of the pilot scale tooling all potential problems and difficulties will be identified and reported.
[OBJ-23] Pilot scale testing and evaluation
• The parts produced will be thoroughly examined and the efficiency of the mould will be assessed.
Definition of application studies
[OBJ-24] Three types of parts are to be studied: one in infusion, another in RTM and another as profile in pultrusion.
Indicative production requirements such as production volume and time to delivery will be defined here. The Smart Tooling Design Framework and Procedures will be employed for the detailed design of the tooling.
[OBJ-25] Development of a functional gelcoat for the tool surface
The development of a suitable coating for the inner surface of the mould tool presents a challenge in that it should be able to withstand the thermal cycling without degradation, and have sufficiently low surface energy to prevent component adhesion to the tool during de-moulding.
[OBJ-26] Manufacturing and assembly of smart tooling
The manufacturing of the application studies tooling will be the objective of this task. For all tooling, the fabrication techniques derived will be applied. All tools will be examined for dimensional accuracy and surface roughness (Class A requirement will be sought).
[OBJ-27] Test program execution
The trial production runs will be conducted in this task. Apart from nominal operation the production will include deliberately faulty actions in order to explore the limits of the novel tooling technology developed.
[OBJ-28] Validation of the smart tooling concept
This task entails the overall assessment of the innovative tooling technology. The first part will involve the trial production results. The second part will emphasize on the validation of the numerical models and tools that comprise the Mould Design Framework.
Smart tooling technology integration to pilot scale
[OBJ-29] To develop a techno-economic model for the evaluation of the proposed smart tooling technology in order to assess its viability
The evaluation will take into account:
• The market and marketing analysis for the new/improved project (e.g. anticipated sales, market share etc.)
• The definition and planning of the production process (e.g. consumables costs, labour costs, equipment costs, machine times etc.)
• The estimation of the economic results of the project (e.g. financial analysis, profit and, impact on economy etc.)
[OBJ-30] To propose and develop a cost- based decision making tool for the selection of smart tooling components and of suitable parameters of the production process
• Multicriteria decision analysis problem, including both qualitative and quantitative criteria
• Models will be embedded in a robust decision making framework to produce a sound, easy to use model that will provide practitioners with a powerful decision making tool
[OBJ-31] The lifecycle of the tooling will be assessed and provisions for improving its sustainability will be developed
Dissemination and Exploitation
[OBJ-32] To perform an exploitation assessment of the developed technologies
To prepare the ground for the exploitation of the project's outcome, this task will closely observe the progress of the technical tasks and perform a detail account of materials, equipment and personnel in order to form a concise view of the operation cost of all methods and procedures. An additional task is to relate the developments and their potential exploitation to their technological readiness level as well.
[OBJ-33] To disseminate information about the technological achievements and present the results to stakeholders of the manufacturing sectors (automotive, construction, aerospace, certification organisations etc).
Project Results:
WP1 - Definition of functional specifications [M1-M12]
Summary of progress towards objectives
Task 1.1: Smart tooling materials database
A tooling materials database has been created and maintained.
Task 1.2: Application of smart tooling concept to plastics and composites manufacturing: a detailed exploitation plan
The identification of exploitable results and the assignment of risks as well as their prioritization will aid in the development of a valuable exploitation plan for all actors involved. These results will provide insight and guidance for the exploitation activities in short and long term.
Task 1.3: Functional specifications for “smart” tooling technologies implementation
The contribution to Task 1.3 was the list of functional specifications of the smart tooling in terms of three input technologies to the smart tooling, namely: the effective nano-doping of the tooling matrix [UoA], the embedded sensing of cure and flow in the tooling [INASCO], the PZT actuators for demoulding [INVENT] and finally the specs for the temperature control system performance in the smart tooling operation [UoA].
In addition to sensors and actuators there were both heating and cooling systems prescribed [FIBRETECH, UoP] and surface treatment approaches [TECNALIA].
WP2 – Heat management technology [M4-M15]
Summary of progress towards objectives
Task 2.1: Modelling, testing, calibration and optimisation of integral heat element configurations for tooling
The main objective of this task was to investigate the capabilities of available heating elements and calibrate their use. As it described in the Annex I of the GA, the main concept for the heating element is to utilize a number of carbon fiber layers as a heating element based on Joule or resistance heating principles.
This technology, called FIBRETEMP, is patented by FIBRETECH and is currently used mainly for open moulds. According to the best practices established by FIBRETECH, the carbon fiber layers that comprise the heating element along with the rest of the layers are laid on a master model in dry form and a resin infusion technique is used to impregnate the fabrics and create the final tool
Following a detailed evaluation of the heating element configurations it was shown that the FIBRETEMP-system, using carbon fabrics as resistance heating elements, achieves the best uniformity of heating and the heating rates reach the maximum possible for the resin-system. In addition, numerical approaches and tools are able to model and predict the temperature field produced.
Task 2.2: Modelling, testing and optimisation of tooling cooling systems
It has been demonstrated that for the “smart”-tooling perforated honeycomb will be the best choice for cooling because of its drapability and uniformity. An integrated tubing network of cooling elements does not meet the specifications targeted for the tooling.
Task 2.3: Enhancement of tooling materials thermal properties through matrix nano-doping
The main finding was that only a marginal increase in thermal properties can be obtained through nano-doping of the tested resin systems. However, impedance analysis indicates that dielectric spectroscopy monitoring of real time dispersion processes involving CNTs in epoxies has great potential in (i) elucidating dispersion processes and (ii) providing a means of quantitatively characterizing the dispersion efficiency of CNTs in epoxies with a view to optimization and standardization.
WP3 – Smart tooling surface development [M4-M15]
Summary of progress towards objectives
Task 3.1: Tooling surface materials and process definitions
A complete guide for tooling surface preparation has been issued. It covers all aspects of the mould surface making.
Task 3.2: Development of surface configurations (preparation, testing, characterisation, evaluation)
A new gelcoat formulation, for the mould surface, has been developed and successfully tested at coupon level. It remains to be seen its application at the actual tool surfaces and its long term behaviour. In addition, thermal spraying techniques have been developed and also successfully tested and characterized. Complete roadmaps for surface configurations have been issued. Finally a procedure for surface optimization has been devised and thoroughly investigated.
Task 3.3: Development of repairable tooling surfaces
Metallic coatings are easily repairable as it was expected. For the gelcoat coatings the situation is not straight forward. The doped gelcoat has a high glass transition temperature, a high surface hardness and good abrasion resistance. The advantage is that it is resistant to scratches and accidental damages. This means that damage is not very likely to occur and that this gelcoat is very difficult to sand and polish to high gloss. If however damage occurs, it can be repaired with a specially formulated repair kit. This is the same tooling gelcoat with different fillers making it polishable.
WP4 – Sensor / Actuator Technology [M4-M15]
Summary of progress towards objectives
Task 4.1: Adaptation and testing of integrated flow and reaction sensing
A new flow sensor and the associated DAQ and S/W [INASCO] have been developed and validated under representative processing conditions. In addition, mounting fixtures for flow and cure sensors have been developed to accommodate their introduction into the “smart” tooling.
Task 4.2: Temperature sensing in smart tooling
The principles and major parts of the temperature control cluster have been developed and tested [UoA and INASCO] under simulated and experimental conditions.
Task 4.3: Development of in-tool piezo-electric actuation system – De-moulding function
The required analysis steps for the selection of operational and placement characteristics for the de-moulding actuators have been established. Potential types of actuators have been examined and tool response has been estimated [CIDAUT and INVENT].
WP5 – Software framework for smart tooling design [M4-M18]
Summary of progress towards objectives
Task 5.1: Design of software structure, numerical tools and interface
A complete analysis sequence that can be used in the design process for the smart mould has been set-up and analyzed. The sequence included all foreseen steps. It was demonstrated that it is possible to apply this chain sequence in order to account for as much parameters and physical effects as possible. Furthermore, a reporting system has been established which will permit the distribution of analysis results to all actors involved in the design cycle of the tooling
Task 5.2: Incorporation of models for flow, thermal, structural and process control
Coupled and uncoupled analyses have been carried out to assess thermal, mechanical and electrical behaviour of composite moulds, the filling of the mould and the resin curing process. In addition issues such as cure monitoring, material state models and process optimization have been addressed. Communication channels between different codes have been explored and exhibit sufficient intra-link automation for data exchange and manipulation.
Task 5.3: Development of automation functionalities for the smart tooling design software framework
The work has been focused on the segments of an Integrated Design Environment for a “smart” tooling structure instead of the data management and work flow management automations which are inherent in most of today’s tools and seamlessly integrated into the tools selected in the framework of the COEUS-TITAN project. A framework of Integrated Design Environment has been proposed. The concept of “smart” tooling design as described above adheres also to the principles of concurrent engineering. The process is an interactive one with continuous feedback. It is left up to the beneficiary’s internal procedures on how to implement it. It was demonstrated that it is possible to apply this chain sequence in order to account for as many parameters and physical effects as possible. The document should be treated as one that will involve with the progression of works and needs to be modified accordingly when need be.
Task 5.4: Implementation and interfacing for techno-economical models
S/W implementation of the techno-economic model has been completed. All major categories of the smart tooling cost are included. The operator has a clear view of the most costly element and consideration of how to reduce the cost.
WP6 – Smart tooling technology integration to pilot scale [M10-M27]
Summary of progress towards objectives
Task 6.1: Design of tooling cavity
After completion of the conventional RTM pre-design of the tool, the composite part was designed. Both designs served as input for the composite tool design, which was additionally optimized for smart features integration.
The pultrusion post former consists of 3 solid blocks that are clamped together enveloping the T-section profile. The blocks were designed with a sandwich design approach allowing an efficient manufacturing. The blocks clamping was realized with an external clamping frame.
Task 6.2: Automated design of smart tooling components
A. Design of heating and venting system
On the basis of the composite tool design, the heating systems were integrated by heating carbon fibres directly. This approach allows for a smooth heat distribution in combination with no additional parts in the tool, since the heating is a structural element as well. For the RTM mould, the desired temperature of 180°C (200°C max) were realized with approximately 15 Volts driving voltage and normal insulation. The heating is approximately rated at about 1.500W/m². In the case of the pultrusion postformer, 10 Volts, minimal insulation and 3 heating segments a temperature distribution from 160°C to 120°C was achieved. This allows for an innovative controlled temperature distribution in the postformer.
B. Flow sensors
In placing the flow sensors it was decided to perform a flow simulation analysis of the infusion process. The software RTMWin© was used for the flow simulation, and the geometry was generated based on the CAD files for the part provided by INVENT. The location of the flow sensors should indicate whether the filling progresses as planned in terms of arrival times and within the injection window for the specific resin and process conditions. As a result, the flow simulation was conducted successfully with a filling time of 140s. Furthermore, 4 flow sensors were placed.
C. Piezoceramic Actuation
With the performed optimization of the ribs in the RTM tool design, the piezoceramic actuators were then integrated. Both actuator types were integrated (patch & stack actuator). Modal and harmonic analyses were performed with both types of actuators. Close attention was given to the stresses in the interface between tool cavity and part. Both actuation methods for de-moulding were evaluated and the possible stress maxima benchmarked against each other. It was observed that the stack actuators provide stresses in the tool-part interface of an order of magnitude greater than the patch actuators. Since, the patch actuators are more convenient to integrate an require less expensive driving hardware it was decided to integrate both type and benchmark them in the pilot scale part manufacture to verify the simulation results. Therefore, 3 stack actuators and 6 patch actuators at several crucial locations were decided to be integrated in the pilot scale tool.
D. Surface Treatment
The RTM tool surface needs to withstand heating and cooling cycles, have good chemical resistance to the resins used to mould parts and allow the possibility to perform repairs in case of accidental damages. These properties were achieved by formulating a new epoxy Gelcoat with a high Tg by making a custom selection of nano and mineral fillers. The Pultrusion post-former is used under a constant temperature. The main challenge at the post former is the abrasion. The research conducted shows that a pure metallic coating is more suitable for the post-former and it can be applied by direct spraying the surface of the ready post former tool. The metallic coating can be sanded and polished to a high gloss. Repairs are possible by spraying more material and repeating the finishing and polishing steps.
Task 6.3: Integration of heating/cooling systems to smart tooling
New techniques for the integration of heating and cooling systems have been implemented. The carbon fibers are used as resistive heating elements. In addition all auxiliary systems have also been introduced into the tooling structure. These include the electrodes for the connection to the power source and the wiring of the circuit
Task 6.4: Integration of sensors and actuators to smart tooling
Employing new design approaches and analyses sets of cure/flow monitoring sensors, piezo patches as well as temperature sensors have successfully integrated onto the tooling. This includes all cable routing and new mounts and drivers as well as new DAQs.
Task 6.5: Pilot scale smart tooling manufacturing
A pilot RTM tool has been produced which incorporates all developed technologies (thermal management system and control, flow and cure monitoring and piezo actuators for resin facilitation / demoulding). A series of new analysis procedures and tools as well as new data acquisition S/W and H/W have been devised and produced. The first edition of a smart RTM tool has been achieved.
Task 6.6: Pilot scale testing and evaluation
A complete experimental infusion program was devised and implemented. The final tooling has employed all developed technologies and systems within COEUS-TITAN and put them to test. It seems that the developed tools and procedures work satisfactorily and their use could be used to optimize the tooling design and the process. However, certain issues still need to be further investigated, calibrated and used from a different perspective in order to realize their full potential.
Issues to devote attention to:
1. Standardization of test set-up
2. Standardization of process parameters and procedures
3. Calibration of various sensors and devices according to established procedures
4. Detailed recording of all activities related to the infusion trials
WP7 – Smart tooling application studies [M22 – M36]
Summary of progress towards objectives
In this work package the technological elements developed throughout the project (materials, processes and analysis tools) will be validated in selected application studies of the entire procedure from the tooling design to the actual production run. Taken into account will also be the results from the pilot tool activities and runs. The efforts entailed:
• Definition of application studies
• Manufacturing and assembly of smart tooling
• Test program execution
• Validation of the smart tooling concept
The work performed in this task is a continuation to the work done in tasks 6.1 and 6.2.
a) Design of RTM part, the RTM tooling cavity, infusion tool and the pultrusion post former design of smart tooling components)
The design follows the requirements of components for aerospace parts. With the experiences, which were acquired in WP6 the part- and mould design was optimized for the smart features integration such as heating, integration of the sensors and actuators.
The pultrusion post former consists of three solid blocks that are clamped together enveloping a T-section profile. The blocks are designed with a solid foam design approach allowing an efficient manufacturing. The blocks clamping is realized with an external clamping frame.
b) Design of heating/cooling system [Fibretech / UoP / EXEL]
Fibretech RTM-tool
On the basis of the composite tool design, the heating system is integrated by current-carrying carbon fibres that are part of the mould-structure and at the same time constitute the heating. So no additional heating elements are needed. The desired temperature of 180° C for the RTM-tool with a heating ramp of approximately 5K per minute is realized with 14-15 V driving voltage and normal insulation. The power is rated at about 1.500 W/m². The active cooling will be performed with cold air through the inner honeycomb.
UoP Infusion-tool
The maximum temperature of the mold is at 196° C, the temperature of the part is at 180° C and the power consumption with a heating ramp of approximately 5K per minute is realized with 14-15 V driving voltage of being approximately 800 W/m². In the case of high temperature manufacturing, the radiation plays important role and cannot be neglected. Using thermal insulation layers or foam blocks above the mold and the part, the energy consumption will be significantly decreased. Using thermal insulation layers (k = 0.05 W/mK) above the CFRP part’s surface, the temperature distribution tends to be more uniform.
EXEL Post former tool
The pultrusion post former, which is divides into three heating segments (one in each block), will be-come a temperature distribution from 160°C to 120°C. This is achieved by a step of heating power within each heating field with a power of 2.000W/m² - 1.450W/m².
c) Positioning of flow and cure sensors [INASCO]
In placing the flow sensors in the RTM tool it was decided to perform a flow simulation analysis of the infusion process. The software RTMWin© was used for the flow simulation, and the geometry was generated based on the CAD files for the part provided by Fibretech. The location of the flow sensors should indicate whether the filling progresses as planned in terms of arrival times and within the injection window for the specific resin and process conditions. As a result, the flow simulation was conducted successfully with a filling pattern determined which led to a minimum of 3 flow sensors being placed.
For the pultrusion case, (1) dielectric sensors onto the T-section profile at the die exit as well as in the resin bath will be provided and connected to the DiAMon Plus™ system
d) Selection and positioning of piezoceramic Actuators [INVENT]
Based on the work done in WP6 the piezoelectric actuation system has be redesigned and added by a new component, the release module.
Piezo patch actuators were used to analyze in detail if the excitation of the mould during infusion had significant and measureable influence to:
• The resin distribution Mould is filled faster, curing could be started earlier
• The mechanical characteristics of the part
Better performance due to improved resin distribution
• assist while demoulding
Introduce constant force as an overlay to the force introduced by the release module
e) Description of an alternative mould-technique (ceramic mould) [CYTEC]
Cytec have developed BMI tooling prepregs for use with high temperature resin systems but they require processing at temperatures above the capabilities of the epoxy syntactic tooling blocks so an alternative pattern material has been developed based on an oxide-based ceramic.
f) Surface treatment (gelcoat) [CLERIUM – TWI]
In WP3 there were created new surface protection formulae (gelcoats). For the RTM tool surface the gelcoat had to withstand heating and cooling cycles, have good chemical resistance to the resin used to mould parts and allow the possibility to perform repairs in case of accidental damages. These specifications were tried to be met by formulating a new epoxy gelcoat with a high Tg by making a custom selection of nano and mineral fillers. Unfortunately the gelcoat failed by building the test tool in WP6. After analysing the possible sources of errors for failure the formula was improved (by CLERIUM). Additionally a complete new formula has been developed by TWI.
Significant results
All lessons learnt from the pilot scale investigations have been incorporated into the four final smart tooling demonstrators. Even though the complexity of the parts increased, modifications and developments were smooth. Four state-of-the-art smart toolings for various composite processing routes have been manufactured. They include all technological add-ons developed in the course of the project.A successful test program has been completed. It has provided insight as to the details of the processing conditions and possible future modifications. The technologies have been validated and their classification in terms of TRL has been performed. The campaign proved that the technologies are the stage where they could be introduced into a smart tooling and ready for the production floor.
WP8 – Techno-economical models [M13 – M36]
Summary of progress towards objectives
Task 8.1: Development of techno-economical models of individual smart tooling technologies
[UoA] team used the Product Breakdown Structure as the basis for detailed cost estimation of Smart tooling technology. The Product Breakdown Structure (PBS) is one of the first vital indispensable steps in producing a cost estimate. The technique to develop a Product Breakdown Structure is to subdivide the final product into its sub-assemblies (parts) in order the product decomposition to be defined. This structure is built from the top down to produce a pyramid-like, hierarchical structure where elements at the bottom are used to produce higher elements in the structure. Additionally, an appropriate item code is used for each element of the structure to indicate the decomposition level.
The second major step in cost estimating method that [UoA] followed was the identification of manufacturing processes of Smart tooling technology and the estimation of the required resources.
For the purpose of cost data collection and estimate, a predefined questionnaire accompanied by detailed instructions for its supplementation, was sent to partners. The questionnaire was made in an excel document, which includes four separate sheets.
• The first sheet contains the Smart Tooling System PBS.
• The second sheet includes the identified production processes, required resources and costs
• The third part contains the labor cost divided into two different costs: set-up cost and run-time cost
• At the final sheet of the excel document the sum of cost material, labor and other costs is calculated.
The existence of significant uncertainties in Smart Tooling manufacturing affects the ability of experts to perform accurate cost estimation. This is a commonly recognised problem during new technology systems development projects. The use of the cost – risk analysis technique is considered to be an effective way to handle cost uncertainty. In order the technique to be applied in the COEUS-TITAN techno-economic model, the [UoA] team developed a simulation module, using the @Risk Software Tool. This tool is an Excel Add-on S/W, which enable users to define stochastic variables and parameters, perform Monte Carlo simulation and calculate the probability density function of output variables (e.g. total cost).
Task 8.2: Cost analysis based decision making for selection of smart tooling components
The approach developed by the University of the Aegean comprises two major stages as follows:
1. Selection and assessment of the smart tooling system components based on the specifications of the composite parts to be produced by the tool itself. Thus, Stage I includes a) the definition of specifications for the production of composite parts, (b) the selection of smart tooling subcomponents based on the defined specifications, (c) the synthesis of three alternative smart tooling systems based on the selected components, all satisfying the defined specifications and (d) the assessment of the alternative systems with respect to robust criteria. This Stage has been implemented in an Excel‐based system ('Selection of alternatives').
2. Selection of the optimum smart tooling system.; For this purpose, the 'Super Decisions' software created by Saaty (2004) was used in order to assess the three alternative smart tooling systems and select the most suitable one.
Based on the part specifications that are provided as inputs to the system and the correlations the selection algorithm defines the exact tooling components, subcomponents or features of a standard system, called Middle range system.
Two more systems are also defined that satisfy all specifications. The first is the High end system, which alters the surface technology type and uses nano-doped gelcoat instead of standard gelcoat. The second alternative is created by removing the monitoring and actuation systems from smart tooling components, thus defining the Low end system.
The next step in the decision analysis process is the definition of the selected subcomponents/features of each of the three alternative smart tooling systems, so that when the optimum system is selected the composition of the optimal tooling system can be reviewed. In order to assess the three alternative smart tooling technologies generated in the previous stage and select the one most suitable, we have developed a process that comprises seven steps. This process has been implemented in the 'Super Decisions' software created by Saaty (2004) that utilizes the ANP model. The structure of the ANP model presented described by its clusters and elements and the connections between them. These connections indicate the flow of influence among the elements.
Task 8.3: Lifecycle Assessment of innovative tooling
There was a substantial change of scope from the original planned work due to the necessity of shifting resources to surface finish developments – a key technology for the sustainability of composite “smart” tooling concepts.
From the limited data available it is demonstrated that new approaches for the construction of the master tool model could lead to eventual savings in time and resources (human, energy savings, etc.) when compared to conventional approaches. For the infusion approach it seems that that the energy requirements are comparable to current metallic moulds.
Significant results
Task 8.1: Development of techno-economical models of individual smart tooling technologies
Development of the cost estimation and cost risk modules
Task 8.2: Cost analysis based decision making for selection of smart tooling components
Development of an assessment and selection tool for smart tooling that uses the “Super Decisions” software to propose the optimum smart tooling based on the user’s requirements.
Task 8.3: Lifecycle Assessment of innovative tooling
From the limited data it seems that the smart tooling could be competitive to conventional tooling with all additional technologies integrated.
WP9 – Dissemination and Exploitation [M24 – M36]
Summary of progress towards objectives
Officially this WP would have started at M24. However, due to the default of partner EUREXCEL and the necessity of establishing a project web-site, under the dissemination activities, some effort was expended by partner [CIDAUT] earlier to that.
The overall objectives have been achieved. The financial and technological evaluation of all new technologies and what benefits may be derived has been performed. Novel operational add-ons and their efficient management could be a desired feature of such “smart” tooling that could make their introduction and use possible when compared to conventional tools even though their initial cost may be higher. The amortization from their use and the benefits from the quality of parts produced could prove to be an offsetting factor in the initial investment.
A limited but much focused dissemination effort has been undertaken. The industrial audiences addressed are the main customers and users of such technologies. Aside for the industrial exposure there were also several scientific publications and presentations to conferences.
Potential Impact:
The results indicate that some of the technologies have reached a maturity level that will allow their immediate exploitation while some other key technologies need further work. Critical issues may hamper initial exploitation estimates and their introduction into a “smart” tooling in the immediate future. It is recommended that a holistic approach be followed for the introduction and integration of technologies in the “smart” tooling.
The project output consists of a set of technologies around the design, manufacturing and operation of innovative process tooling for composite materials manufacturing. The project deals with creation of knowledge on innovative heating and thermal management methods for the smart tooling, robust surface treatment formulations for the tooling, the implementation of (tool-integrated) process sensing, actuation and control in its operation, the organisation of various design aspects around the tooling functionalities and, finally, the integration and demonstration of the tooling operation.
The impact to the competitiveness for the EU moulding industry arises from the fact that the novel technologies may offer:
• Moulds at a competitive price
Outcome: Composite moulds are at a higher price range to that of conventional moulds
Prognosis: Reducing machining costs would effectively lead to reduced mould fabrication costs by at least 20-30% compared to a metal mould for the same level of production (price reduction).
• A reduction on labour intensive operations (to cover the lower labour cost of other com-petitors)
Outcome: This has not been verified yet in the project. Possible automation in the layup and integration of technologies is required.
Prognosis: Need automation in the tool manufacturing process that takes into account the technological add-ons in the design and integration activities. If this is successfully implemented an additional cost savings of 15-20% may be achieved.
• Knowledge intensive-high quality moulds (to counter the USA possible growth in the sec-tor)
Outcome: The project’s results indicate that this could be achieved
Prognosis: Such a product could be furnished in the short-term (1 year from now) if the technological stoppers identified could be resolved.
• Energy savings in the production process
Outcome: The thermal management systems, the embedded heating, the cure monitoring and possibly the efficient control in the future will definitely lead to energy savings. In its current state the work also demonstrates energy savings.
Prognosis: The embedded mould heating system in conjunction with the heat management system and the lower thermal capacity of the mould material may effectively reduce the energy consumption for part manufacturing up to 10-20%.
• Savings in faulty parts/scrap
Outcome: The monitoring process could be used to reduction of faulty parts. Better ma-terial state models are in need.
Prognosis: A reduction of faulty parts/scrap of 15% has been demonstrated in industrial applications
It is seen that despite the efforts and improvements of the technological add-ons key issues still need further action (surface coatings and control). However, in all other areas the issues remain under control or have been resolved in their entirety. The SWOT analysis of the final results are rather encouraging. Furthermore, the priority intervention (i.e. a measure of needed revisit of key technological issues) level has been decreased in most of the technologies. This indicates that after the 18M check point the effort spent has led to improvements and better understanding of the technologies involved. However, certain areas still need further work and some of them they may entail technological risks. In any case the technologies already available are a step further towards the “smart” tooling implementation and such key features may be incorporated in the immediate future.
The potential of the technological exploitation of results has been mapped out in terms of technological readiness level (intervention priority) and risk. The comparison for the developments was made between the 18M check point and the final status. The analysis indicate that certain technologies (thermal management system, cure monitoring, tool construction methods) could be of immediate exploitation while others (actuators for resin infiltration, demoulding) could be introduced without much effort. The exploitation potential of the coating/surface finish for the RTM tool needs further validation before its commercial exploitation while cure based control shows promising results at the simulation level.
List of Websites:
www.coeus-titan.eu
COEUS-TITAN aims to develop innovative, robust and easy to heat composite moulds (both closed and open), through addressing all those issues that currently prevent composite tooling from being viable alternative for the industrial production of plastic and composite parts across a wide range of manufacturing routes.
Most important Innovations are:
i. Embedded heating elements, based on the carbon reinforcement of the mould, close to the mould-part interface demanding less energy.
ii. Incorporation of flow, temperature and cure sensors that will enable full automatic control of the process.
iii. Layout of a cooling system consisting of a conformal (following the contour of the part) tubing network.
iv. Use of piezoceramic film actuators which will induce micro-vibrations and thus assist resin flow inside the cavity. Such actuators on the edges can be used for demoulding and thus reducing tool complexity and demoulding time.
Integration of these functionalities into a single “smart” mould is anticipated to impart a significant advancement of the composite and plastics manufacturing industry.The aspects of this innovative tooling concept pursued and developed in the course of the project are listed below:
A low cost, thermally insulated GRP/CFRP composite tooling base acting as the structural reinforcement of the mould cavity.
A mould cavity constructed by a doped laminated, thermally conductive thermoset composite, incorporating the following systems:
A heating system comprised of the carbon fibre reinforcements situated beneath the mould surface among a number of high thermal conductivity nano-doped layers that facilitate uniform heating. The heating system is also a load bearing part of the mould.
A conformal cooling system comprised of a conformal network of channels that circulate a heat transfer fluid.
Low friction, high wear-resistant surface layers, implemented either by coating or by doping out of resins with SiC nano-fillers
Piezo-electric actuators that induce micro-vibrations assisting resin flow.
A monitoring system comprising of embedded flow, temperature and curing sensors, which supply data to a central management unit that controls process parameters.
A set of analysis tools for tooling design promoting a distributed engineering approach:
Heat management and simulation of the heating-cooling procedures
Structural and thermal optimisation analysis
Resin flow simulation and cavity filling optimisation
Process parameter optimisation
Sensing and control system design
Coupled model for the full system simulation and optimisation
A techno-economical model for the selection of the production process and the appropriate level of tooling functionality on the basis of optimum production cost.
Project Context and Objectives:
Definition of functional specifications
[OBJ-1] Development of “smart” tooling materials database
• Almost every aspect of the innovations proposed in the project relies on material technology. It is therefore necessary to obtain a database of the candidate materials to be utilised for the smart tooling concept in the course of the project.
[OBJ-2] A detailed exploitation plan for the application of “smart” tooling concept to plastics and composites manufacturing
• First, to gather the state-of-the-art in key manufacturing methods currently used for composites and plastics. Identify the use of composite tooling at high end manufacturing processes and define the extent of application for the smart tooling concept (heating through the carbon reinforcement of CFRP's, modification of surface properties through nano-doping, novel coatings, integrated sensors and actuators).
• Secondly, consolidate the beneficiaries plans in using the smart tooling concept will be further analysed and the specific actions of the beneficiaries for the exploitation of the COEUS-TITAN technology will be defined.
[OBJ-3] Functional specifications for “smart” tooling technologies implementation
• The aim of this task is to identify the data required in order to design a tooling for either an open or closed mould process. Existing designs of tools and dies for typical mass production parts and high-tech low production volume parts (e.g. aeronautical) will be examined in terms of their specifications. The definition of the tooling for the application case studies (on RTM and pultrusion) will also be made here, along with the definition of the simpler experimental tooling to be considered for the pilot scale study. Based on the information gathered the design specifications (heating/cooling system, sensing/actuation and surface configuration) to be satisfied by the proposed development will be analysed.
Heat management technology
[OBJ-4] To fully investigate the capabilities of available heating elements and calibrate their use -Modelling, testing, calibration and optimisation of integral heat element configurations for tooling heating systems
• Heat a composite CFRP structure using the carbon fibres as resistance heating elements.
• Detailed evaluation of the different heating element configurations and the selection of the most convenient solution to be applied in the course of the project
• Development of numerical analysis models for the simulation of the heating system operation will be performed.
• Electro-thermal analysis models able to predict the temperature field over the heating element, given the electrical circuit characteristics
[OBJ-5] To determine the parameters of the cooling system operation - Modelling, testing and optimisation of tooling cooling systems
• Investigate a system embedded into the tooling, comprising of a tubing network that will circulate a cooling fluid. The main issue that must be dealt with is possible heat losses from the heating elements due to heat conduction.
• Development of numerical analysis models for the simulation of the cooling system operation
[OBJ-6] To optimise the thermal properties of the mould cavity materials - Enhancement of tooling materials thermal properties through matrix nano-doping
Smart tooling surface development
[OBJ-7] Definition of tooling surface materials and processes - Selection of the materials and manufacturing route for the preparation of the part prototypes that will be the basis for the building up of the “smart” tools
• Employ state of the art technologies and the best practices for preparing the master model surface, choosing the right materials and applying polymer surface resins. Tooling block materials are available in different densities and with different properties. A tooling block material needs to be machined to create a physical model to be used for mould building. The surface of this model will be copied by the epoxy gelcoat and used to create the mould surface. This is why it is very important to decide on the surface requirements at an early stage.
[OBJ-8] Study and develop manufacturing solutions in respect to the optimisation of the tooling surface quality and durability
• These solutions aim to enhance the tribological properties using the following two approaches:
- Doping of the surface layers with nanofillers
- Application of wear resistant coatings
[OBJ-9] Development of repair techniques for “smart” tooling surfaces
• The selected tool surface configurations will be evaluated in terms of repairability. The worn specimens will be repaired either by standard composite repair techniques in the case of the doped gel-coat configuration or by re-application of the coating.
Sensor / Actuator Technology
[OBJ-10] Adaptation and testing of integrated flow and reaction sensing
• Development of dielectric flow and reaction (cure) monitoring sensors as well as DAQs and mountings embedded into the “smart” tooling. Several small mould mock-up specimens will be fabricated with integrated capacitive elements and their wiring. Ultrasound sensors will also be investigated.
[OBJ-11] Development of temperature sensing in “smart” tooling through the use of integrated thin film technology
• Embedding of thin films in resins under the surface layer of the smart mould construction as temperature sensors
[OBJ-12]Development and testing of the tooling temperature control system
• Supply data to a central management unit that controls process parameters through the use of the embedded monitoring system comprising of embedded flow, temperature and curing sensors. These measurements will form the input to the data acquisition boards.
- The output of the system (through the computer’s D/A interface) will drive the temperature controllers of the heating system.
[OBJ-13] Development of in-tool piezo-electric actuation system – De-moulding function
• Introduce piezoelectric actuators to “automate” the de-moulding process. To accomplish this, the use of patch- actuators will be considered. Patch-Actuators are composed of flat piezo-ceramic plates (0.1 to 0.5 mm) cased inside a ductile polymer film. By applying a voltage to these patches, they generate a deformation of the ceramic which introduces a shear force into the structure.
Software framework for smart tooling design
[OBJ-14] Review of commercially available software for CAD/CAM/CAE, which implement modules specific for the design and simulation of composites manufacturing processes
• Capabilities of simulation
• Input/output file formats
• Interfaces with other more generic CAE tools
• Complementarity of capabilities
• Accuracy
• Usability
• File interfaces & Capacity for interoperability
[OBJ-15] Incorporation of models for flow, thermal, structural and process control
• According to the requirements and capabilities of the process simulation software, the “peripheral” models will be arranged, in terms of data content and format. During a moulding process (either open or closed mould), three stages/processes will be investigated:
1. Mould / tool preheating
2. Filling process
3. Curing /cooling
[OBJ-16] Development of automation functionalities for the smart tooling design software framework
• The overall outcome intended is to configure the design framework in such a way that it will require just the CAD file of the product, material details, time and cost constraints and any other specifications in order to produce (with minimal user intervention/manipulation) the mould design and the full set of process control parameters. This eventually will lead to a user-defined Integrated Design Environment.
[OBJ-17] Implementation and interfacing for techno- economical models
• The implementation of the developed techno-economical models in the software framework as a separate module. Their function will be to estimate the total cost of a part's production depending on the design features and the components included in the mould construction.
Smart tooling technology integration to pilot scale
[OBJ-18] Design of tooling cavity for pilot scale implementation
• The starting point will be the design of the tooling cavity that will include the surface layers, the heating elements and the cooling system. The design aspects to be considered for the manufacturing of the tooling cavity should be able to address:
- Use of a high Tg resin or polymer
- Doping of the resin with nano-sized particles
- The setup of the heating elements
- The incorporation of the cooling system
[OBJ-19] Design a structure that will support the tooling cavity during the high pressure loadings of the RTM and pultrusion processes
[OBJ-20] Integration study of heating/cooling systems
• Although the heating elements are essentially the carbon fibres, the realisation of the heating system requires a set of auxiliary components that need to be introduced into the tooling structure. These are the electrodes for the connection to the power source and the wiring of the circuit.
• The integration of the cooling system, depending on the form selected will also bear upon the manufacturing procedure. The goal of this task is to provide techniques to combine the fabrication procedure for the tooling cavity with the placement of the components of the cooling system.
[OBJ-21] Integration study of sensing/actuation systems
• The first is to embed fittings for the attachment of the sensors during the cavity lay-up. The second is to similarly embed cured resin “plugs”, through the thickness of the structure. Drilling through these plugs will enable fitting of the sensors without compromising the fibres. The acoustic sensors, if selected for application, will pose no significant problem as they will be fitted in the mould base, just under the cavity layers.
• The patch-actuators are in fact tailored to be laminated inside a composite structure; therefore their integration in the mould is a trivial task. The accommodation of the required wiring for all active components (sensors/actuators) will also be detailed in this task.
[OBJ-22] Manufacturing of pilot scale tooling and assembly
• The work of this task is the actual fabrication of the pilot scale tooling given the design and instructions derived thus far. During the manufacturing of the pilot scale tooling all potential problems and difficulties will be identified and reported.
[OBJ-23] Pilot scale testing and evaluation
• The parts produced will be thoroughly examined and the efficiency of the mould will be assessed.
Definition of application studies
[OBJ-24] Three types of parts are to be studied: one in infusion, another in RTM and another as profile in pultrusion.
Indicative production requirements such as production volume and time to delivery will be defined here. The Smart Tooling Design Framework and Procedures will be employed for the detailed design of the tooling.
[OBJ-25] Development of a functional gelcoat for the tool surface
The development of a suitable coating for the inner surface of the mould tool presents a challenge in that it should be able to withstand the thermal cycling without degradation, and have sufficiently low surface energy to prevent component adhesion to the tool during de-moulding.
[OBJ-26] Manufacturing and assembly of smart tooling
The manufacturing of the application studies tooling will be the objective of this task. For all tooling, the fabrication techniques derived will be applied. All tools will be examined for dimensional accuracy and surface roughness (Class A requirement will be sought).
[OBJ-27] Test program execution
The trial production runs will be conducted in this task. Apart from nominal operation the production will include deliberately faulty actions in order to explore the limits of the novel tooling technology developed.
[OBJ-28] Validation of the smart tooling concept
This task entails the overall assessment of the innovative tooling technology. The first part will involve the trial production results. The second part will emphasize on the validation of the numerical models and tools that comprise the Mould Design Framework.
Smart tooling technology integration to pilot scale
[OBJ-29] To develop a techno-economic model for the evaluation of the proposed smart tooling technology in order to assess its viability
The evaluation will take into account:
• The market and marketing analysis for the new/improved project (e.g. anticipated sales, market share etc.)
• The definition and planning of the production process (e.g. consumables costs, labour costs, equipment costs, machine times etc.)
• The estimation of the economic results of the project (e.g. financial analysis, profit and, impact on economy etc.)
[OBJ-30] To propose and develop a cost- based decision making tool for the selection of smart tooling components and of suitable parameters of the production process
• Multicriteria decision analysis problem, including both qualitative and quantitative criteria
• Models will be embedded in a robust decision making framework to produce a sound, easy to use model that will provide practitioners with a powerful decision making tool
[OBJ-31] The lifecycle of the tooling will be assessed and provisions for improving its sustainability will be developed
Dissemination and Exploitation
[OBJ-32] To perform an exploitation assessment of the developed technologies
To prepare the ground for the exploitation of the project's outcome, this task will closely observe the progress of the technical tasks and perform a detail account of materials, equipment and personnel in order to form a concise view of the operation cost of all methods and procedures. An additional task is to relate the developments and their potential exploitation to their technological readiness level as well.
[OBJ-33] To disseminate information about the technological achievements and present the results to stakeholders of the manufacturing sectors (automotive, construction, aerospace, certification organisations etc).
Project Results:
WP1 - Definition of functional specifications [M1-M12]
Summary of progress towards objectives
Task 1.1: Smart tooling materials database
A tooling materials database has been created and maintained.
Task 1.2: Application of smart tooling concept to plastics and composites manufacturing: a detailed exploitation plan
The identification of exploitable results and the assignment of risks as well as their prioritization will aid in the development of a valuable exploitation plan for all actors involved. These results will provide insight and guidance for the exploitation activities in short and long term.
Task 1.3: Functional specifications for “smart” tooling technologies implementation
The contribution to Task 1.3 was the list of functional specifications of the smart tooling in terms of three input technologies to the smart tooling, namely: the effective nano-doping of the tooling matrix [UoA], the embedded sensing of cure and flow in the tooling [INASCO], the PZT actuators for demoulding [INVENT] and finally the specs for the temperature control system performance in the smart tooling operation [UoA].
In addition to sensors and actuators there were both heating and cooling systems prescribed [FIBRETECH, UoP] and surface treatment approaches [TECNALIA].
WP2 – Heat management technology [M4-M15]
Summary of progress towards objectives
Task 2.1: Modelling, testing, calibration and optimisation of integral heat element configurations for tooling
The main objective of this task was to investigate the capabilities of available heating elements and calibrate their use. As it described in the Annex I of the GA, the main concept for the heating element is to utilize a number of carbon fiber layers as a heating element based on Joule or resistance heating principles.
This technology, called FIBRETEMP, is patented by FIBRETECH and is currently used mainly for open moulds. According to the best practices established by FIBRETECH, the carbon fiber layers that comprise the heating element along with the rest of the layers are laid on a master model in dry form and a resin infusion technique is used to impregnate the fabrics and create the final tool
Following a detailed evaluation of the heating element configurations it was shown that the FIBRETEMP-system, using carbon fabrics as resistance heating elements, achieves the best uniformity of heating and the heating rates reach the maximum possible for the resin-system. In addition, numerical approaches and tools are able to model and predict the temperature field produced.
Task 2.2: Modelling, testing and optimisation of tooling cooling systems
It has been demonstrated that for the “smart”-tooling perforated honeycomb will be the best choice for cooling because of its drapability and uniformity. An integrated tubing network of cooling elements does not meet the specifications targeted for the tooling.
Task 2.3: Enhancement of tooling materials thermal properties through matrix nano-doping
The main finding was that only a marginal increase in thermal properties can be obtained through nano-doping of the tested resin systems. However, impedance analysis indicates that dielectric spectroscopy monitoring of real time dispersion processes involving CNTs in epoxies has great potential in (i) elucidating dispersion processes and (ii) providing a means of quantitatively characterizing the dispersion efficiency of CNTs in epoxies with a view to optimization and standardization.
WP3 – Smart tooling surface development [M4-M15]
Summary of progress towards objectives
Task 3.1: Tooling surface materials and process definitions
A complete guide for tooling surface preparation has been issued. It covers all aspects of the mould surface making.
Task 3.2: Development of surface configurations (preparation, testing, characterisation, evaluation)
A new gelcoat formulation, for the mould surface, has been developed and successfully tested at coupon level. It remains to be seen its application at the actual tool surfaces and its long term behaviour. In addition, thermal spraying techniques have been developed and also successfully tested and characterized. Complete roadmaps for surface configurations have been issued. Finally a procedure for surface optimization has been devised and thoroughly investigated.
Task 3.3: Development of repairable tooling surfaces
Metallic coatings are easily repairable as it was expected. For the gelcoat coatings the situation is not straight forward. The doped gelcoat has a high glass transition temperature, a high surface hardness and good abrasion resistance. The advantage is that it is resistant to scratches and accidental damages. This means that damage is not very likely to occur and that this gelcoat is very difficult to sand and polish to high gloss. If however damage occurs, it can be repaired with a specially formulated repair kit. This is the same tooling gelcoat with different fillers making it polishable.
WP4 – Sensor / Actuator Technology [M4-M15]
Summary of progress towards objectives
Task 4.1: Adaptation and testing of integrated flow and reaction sensing
A new flow sensor and the associated DAQ and S/W [INASCO] have been developed and validated under representative processing conditions. In addition, mounting fixtures for flow and cure sensors have been developed to accommodate their introduction into the “smart” tooling.
Task 4.2: Temperature sensing in smart tooling
The principles and major parts of the temperature control cluster have been developed and tested [UoA and INASCO] under simulated and experimental conditions.
Task 4.3: Development of in-tool piezo-electric actuation system – De-moulding function
The required analysis steps for the selection of operational and placement characteristics for the de-moulding actuators have been established. Potential types of actuators have been examined and tool response has been estimated [CIDAUT and INVENT].
WP5 – Software framework for smart tooling design [M4-M18]
Summary of progress towards objectives
Task 5.1: Design of software structure, numerical tools and interface
A complete analysis sequence that can be used in the design process for the smart mould has been set-up and analyzed. The sequence included all foreseen steps. It was demonstrated that it is possible to apply this chain sequence in order to account for as much parameters and physical effects as possible. Furthermore, a reporting system has been established which will permit the distribution of analysis results to all actors involved in the design cycle of the tooling
Task 5.2: Incorporation of models for flow, thermal, structural and process control
Coupled and uncoupled analyses have been carried out to assess thermal, mechanical and electrical behaviour of composite moulds, the filling of the mould and the resin curing process. In addition issues such as cure monitoring, material state models and process optimization have been addressed. Communication channels between different codes have been explored and exhibit sufficient intra-link automation for data exchange and manipulation.
Task 5.3: Development of automation functionalities for the smart tooling design software framework
The work has been focused on the segments of an Integrated Design Environment for a “smart” tooling structure instead of the data management and work flow management automations which are inherent in most of today’s tools and seamlessly integrated into the tools selected in the framework of the COEUS-TITAN project. A framework of Integrated Design Environment has been proposed. The concept of “smart” tooling design as described above adheres also to the principles of concurrent engineering. The process is an interactive one with continuous feedback. It is left up to the beneficiary’s internal procedures on how to implement it. It was demonstrated that it is possible to apply this chain sequence in order to account for as many parameters and physical effects as possible. The document should be treated as one that will involve with the progression of works and needs to be modified accordingly when need be.
Task 5.4: Implementation and interfacing for techno-economical models
S/W implementation of the techno-economic model has been completed. All major categories of the smart tooling cost are included. The operator has a clear view of the most costly element and consideration of how to reduce the cost.
WP6 – Smart tooling technology integration to pilot scale [M10-M27]
Summary of progress towards objectives
Task 6.1: Design of tooling cavity
After completion of the conventional RTM pre-design of the tool, the composite part was designed. Both designs served as input for the composite tool design, which was additionally optimized for smart features integration.
The pultrusion post former consists of 3 solid blocks that are clamped together enveloping the T-section profile. The blocks were designed with a sandwich design approach allowing an efficient manufacturing. The blocks clamping was realized with an external clamping frame.
Task 6.2: Automated design of smart tooling components
A. Design of heating and venting system
On the basis of the composite tool design, the heating systems were integrated by heating carbon fibres directly. This approach allows for a smooth heat distribution in combination with no additional parts in the tool, since the heating is a structural element as well. For the RTM mould, the desired temperature of 180°C (200°C max) were realized with approximately 15 Volts driving voltage and normal insulation. The heating is approximately rated at about 1.500W/m². In the case of the pultrusion postformer, 10 Volts, minimal insulation and 3 heating segments a temperature distribution from 160°C to 120°C was achieved. This allows for an innovative controlled temperature distribution in the postformer.
B. Flow sensors
In placing the flow sensors it was decided to perform a flow simulation analysis of the infusion process. The software RTMWin© was used for the flow simulation, and the geometry was generated based on the CAD files for the part provided by INVENT. The location of the flow sensors should indicate whether the filling progresses as planned in terms of arrival times and within the injection window for the specific resin and process conditions. As a result, the flow simulation was conducted successfully with a filling time of 140s. Furthermore, 4 flow sensors were placed.
C. Piezoceramic Actuation
With the performed optimization of the ribs in the RTM tool design, the piezoceramic actuators were then integrated. Both actuator types were integrated (patch & stack actuator). Modal and harmonic analyses were performed with both types of actuators. Close attention was given to the stresses in the interface between tool cavity and part. Both actuation methods for de-moulding were evaluated and the possible stress maxima benchmarked against each other. It was observed that the stack actuators provide stresses in the tool-part interface of an order of magnitude greater than the patch actuators. Since, the patch actuators are more convenient to integrate an require less expensive driving hardware it was decided to integrate both type and benchmark them in the pilot scale part manufacture to verify the simulation results. Therefore, 3 stack actuators and 6 patch actuators at several crucial locations were decided to be integrated in the pilot scale tool.
D. Surface Treatment
The RTM tool surface needs to withstand heating and cooling cycles, have good chemical resistance to the resins used to mould parts and allow the possibility to perform repairs in case of accidental damages. These properties were achieved by formulating a new epoxy Gelcoat with a high Tg by making a custom selection of nano and mineral fillers. The Pultrusion post-former is used under a constant temperature. The main challenge at the post former is the abrasion. The research conducted shows that a pure metallic coating is more suitable for the post-former and it can be applied by direct spraying the surface of the ready post former tool. The metallic coating can be sanded and polished to a high gloss. Repairs are possible by spraying more material and repeating the finishing and polishing steps.
Task 6.3: Integration of heating/cooling systems to smart tooling
New techniques for the integration of heating and cooling systems have been implemented. The carbon fibers are used as resistive heating elements. In addition all auxiliary systems have also been introduced into the tooling structure. These include the electrodes for the connection to the power source and the wiring of the circuit
Task 6.4: Integration of sensors and actuators to smart tooling
Employing new design approaches and analyses sets of cure/flow monitoring sensors, piezo patches as well as temperature sensors have successfully integrated onto the tooling. This includes all cable routing and new mounts and drivers as well as new DAQs.
Task 6.5: Pilot scale smart tooling manufacturing
A pilot RTM tool has been produced which incorporates all developed technologies (thermal management system and control, flow and cure monitoring and piezo actuators for resin facilitation / demoulding). A series of new analysis procedures and tools as well as new data acquisition S/W and H/W have been devised and produced. The first edition of a smart RTM tool has been achieved.
Task 6.6: Pilot scale testing and evaluation
A complete experimental infusion program was devised and implemented. The final tooling has employed all developed technologies and systems within COEUS-TITAN and put them to test. It seems that the developed tools and procedures work satisfactorily and their use could be used to optimize the tooling design and the process. However, certain issues still need to be further investigated, calibrated and used from a different perspective in order to realize their full potential.
Issues to devote attention to:
1. Standardization of test set-up
2. Standardization of process parameters and procedures
3. Calibration of various sensors and devices according to established procedures
4. Detailed recording of all activities related to the infusion trials
WP7 – Smart tooling application studies [M22 – M36]
Summary of progress towards objectives
In this work package the technological elements developed throughout the project (materials, processes and analysis tools) will be validated in selected application studies of the entire procedure from the tooling design to the actual production run. Taken into account will also be the results from the pilot tool activities and runs. The efforts entailed:
• Definition of application studies
• Manufacturing and assembly of smart tooling
• Test program execution
• Validation of the smart tooling concept
The work performed in this task is a continuation to the work done in tasks 6.1 and 6.2.
a) Design of RTM part, the RTM tooling cavity, infusion tool and the pultrusion post former design of smart tooling components)
The design follows the requirements of components for aerospace parts. With the experiences, which were acquired in WP6 the part- and mould design was optimized for the smart features integration such as heating, integration of the sensors and actuators.
The pultrusion post former consists of three solid blocks that are clamped together enveloping a T-section profile. The blocks are designed with a solid foam design approach allowing an efficient manufacturing. The blocks clamping is realized with an external clamping frame.
b) Design of heating/cooling system [Fibretech / UoP / EXEL]
Fibretech RTM-tool
On the basis of the composite tool design, the heating system is integrated by current-carrying carbon fibres that are part of the mould-structure and at the same time constitute the heating. So no additional heating elements are needed. The desired temperature of 180° C for the RTM-tool with a heating ramp of approximately 5K per minute is realized with 14-15 V driving voltage and normal insulation. The power is rated at about 1.500 W/m². The active cooling will be performed with cold air through the inner honeycomb.
UoP Infusion-tool
The maximum temperature of the mold is at 196° C, the temperature of the part is at 180° C and the power consumption with a heating ramp of approximately 5K per minute is realized with 14-15 V driving voltage of being approximately 800 W/m². In the case of high temperature manufacturing, the radiation plays important role and cannot be neglected. Using thermal insulation layers or foam blocks above the mold and the part, the energy consumption will be significantly decreased. Using thermal insulation layers (k = 0.05 W/mK) above the CFRP part’s surface, the temperature distribution tends to be more uniform.
EXEL Post former tool
The pultrusion post former, which is divides into three heating segments (one in each block), will be-come a temperature distribution from 160°C to 120°C. This is achieved by a step of heating power within each heating field with a power of 2.000W/m² - 1.450W/m².
c) Positioning of flow and cure sensors [INASCO]
In placing the flow sensors in the RTM tool it was decided to perform a flow simulation analysis of the infusion process. The software RTMWin© was used for the flow simulation, and the geometry was generated based on the CAD files for the part provided by Fibretech. The location of the flow sensors should indicate whether the filling progresses as planned in terms of arrival times and within the injection window for the specific resin and process conditions. As a result, the flow simulation was conducted successfully with a filling pattern determined which led to a minimum of 3 flow sensors being placed.
For the pultrusion case, (1) dielectric sensors onto the T-section profile at the die exit as well as in the resin bath will be provided and connected to the DiAMon Plus™ system
d) Selection and positioning of piezoceramic Actuators [INVENT]
Based on the work done in WP6 the piezoelectric actuation system has be redesigned and added by a new component, the release module.
Piezo patch actuators were used to analyze in detail if the excitation of the mould during infusion had significant and measureable influence to:
• The resin distribution Mould is filled faster, curing could be started earlier
• The mechanical characteristics of the part
Better performance due to improved resin distribution
• assist while demoulding
Introduce constant force as an overlay to the force introduced by the release module
e) Description of an alternative mould-technique (ceramic mould) [CYTEC]
Cytec have developed BMI tooling prepregs for use with high temperature resin systems but they require processing at temperatures above the capabilities of the epoxy syntactic tooling blocks so an alternative pattern material has been developed based on an oxide-based ceramic.
f) Surface treatment (gelcoat) [CLERIUM – TWI]
In WP3 there were created new surface protection formulae (gelcoats). For the RTM tool surface the gelcoat had to withstand heating and cooling cycles, have good chemical resistance to the resin used to mould parts and allow the possibility to perform repairs in case of accidental damages. These specifications were tried to be met by formulating a new epoxy gelcoat with a high Tg by making a custom selection of nano and mineral fillers. Unfortunately the gelcoat failed by building the test tool in WP6. After analysing the possible sources of errors for failure the formula was improved (by CLERIUM). Additionally a complete new formula has been developed by TWI.
Significant results
All lessons learnt from the pilot scale investigations have been incorporated into the four final smart tooling demonstrators. Even though the complexity of the parts increased, modifications and developments were smooth. Four state-of-the-art smart toolings for various composite processing routes have been manufactured. They include all technological add-ons developed in the course of the project.A successful test program has been completed. It has provided insight as to the details of the processing conditions and possible future modifications. The technologies have been validated and their classification in terms of TRL has been performed. The campaign proved that the technologies are the stage where they could be introduced into a smart tooling and ready for the production floor.
WP8 – Techno-economical models [M13 – M36]
Summary of progress towards objectives
Task 8.1: Development of techno-economical models of individual smart tooling technologies
[UoA] team used the Product Breakdown Structure as the basis for detailed cost estimation of Smart tooling technology. The Product Breakdown Structure (PBS) is one of the first vital indispensable steps in producing a cost estimate. The technique to develop a Product Breakdown Structure is to subdivide the final product into its sub-assemblies (parts) in order the product decomposition to be defined. This structure is built from the top down to produce a pyramid-like, hierarchical structure where elements at the bottom are used to produce higher elements in the structure. Additionally, an appropriate item code is used for each element of the structure to indicate the decomposition level.
The second major step in cost estimating method that [UoA] followed was the identification of manufacturing processes of Smart tooling technology and the estimation of the required resources.
For the purpose of cost data collection and estimate, a predefined questionnaire accompanied by detailed instructions for its supplementation, was sent to partners. The questionnaire was made in an excel document, which includes four separate sheets.
• The first sheet contains the Smart Tooling System PBS.
• The second sheet includes the identified production processes, required resources and costs
• The third part contains the labor cost divided into two different costs: set-up cost and run-time cost
• At the final sheet of the excel document the sum of cost material, labor and other costs is calculated.
The existence of significant uncertainties in Smart Tooling manufacturing affects the ability of experts to perform accurate cost estimation. This is a commonly recognised problem during new technology systems development projects. The use of the cost – risk analysis technique is considered to be an effective way to handle cost uncertainty. In order the technique to be applied in the COEUS-TITAN techno-economic model, the [UoA] team developed a simulation module, using the @Risk Software Tool. This tool is an Excel Add-on S/W, which enable users to define stochastic variables and parameters, perform Monte Carlo simulation and calculate the probability density function of output variables (e.g. total cost).
Task 8.2: Cost analysis based decision making for selection of smart tooling components
The approach developed by the University of the Aegean comprises two major stages as follows:
1. Selection and assessment of the smart tooling system components based on the specifications of the composite parts to be produced by the tool itself. Thus, Stage I includes a) the definition of specifications for the production of composite parts, (b) the selection of smart tooling subcomponents based on the defined specifications, (c) the synthesis of three alternative smart tooling systems based on the selected components, all satisfying the defined specifications and (d) the assessment of the alternative systems with respect to robust criteria. This Stage has been implemented in an Excel‐based system ('Selection of alternatives').
2. Selection of the optimum smart tooling system.; For this purpose, the 'Super Decisions' software created by Saaty (2004) was used in order to assess the three alternative smart tooling systems and select the most suitable one.
Based on the part specifications that are provided as inputs to the system and the correlations the selection algorithm defines the exact tooling components, subcomponents or features of a standard system, called Middle range system.
Two more systems are also defined that satisfy all specifications. The first is the High end system, which alters the surface technology type and uses nano-doped gelcoat instead of standard gelcoat. The second alternative is created by removing the monitoring and actuation systems from smart tooling components, thus defining the Low end system.
The next step in the decision analysis process is the definition of the selected subcomponents/features of each of the three alternative smart tooling systems, so that when the optimum system is selected the composition of the optimal tooling system can be reviewed. In order to assess the three alternative smart tooling technologies generated in the previous stage and select the one most suitable, we have developed a process that comprises seven steps. This process has been implemented in the 'Super Decisions' software created by Saaty (2004) that utilizes the ANP model. The structure of the ANP model presented described by its clusters and elements and the connections between them. These connections indicate the flow of influence among the elements.
Task 8.3: Lifecycle Assessment of innovative tooling
There was a substantial change of scope from the original planned work due to the necessity of shifting resources to surface finish developments – a key technology for the sustainability of composite “smart” tooling concepts.
From the limited data available it is demonstrated that new approaches for the construction of the master tool model could lead to eventual savings in time and resources (human, energy savings, etc.) when compared to conventional approaches. For the infusion approach it seems that that the energy requirements are comparable to current metallic moulds.
Significant results
Task 8.1: Development of techno-economical models of individual smart tooling technologies
Development of the cost estimation and cost risk modules
Task 8.2: Cost analysis based decision making for selection of smart tooling components
Development of an assessment and selection tool for smart tooling that uses the “Super Decisions” software to propose the optimum smart tooling based on the user’s requirements.
Task 8.3: Lifecycle Assessment of innovative tooling
From the limited data it seems that the smart tooling could be competitive to conventional tooling with all additional technologies integrated.
WP9 – Dissemination and Exploitation [M24 – M36]
Summary of progress towards objectives
Officially this WP would have started at M24. However, due to the default of partner EUREXCEL and the necessity of establishing a project web-site, under the dissemination activities, some effort was expended by partner [CIDAUT] earlier to that.
The overall objectives have been achieved. The financial and technological evaluation of all new technologies and what benefits may be derived has been performed. Novel operational add-ons and their efficient management could be a desired feature of such “smart” tooling that could make their introduction and use possible when compared to conventional tools even though their initial cost may be higher. The amortization from their use and the benefits from the quality of parts produced could prove to be an offsetting factor in the initial investment.
A limited but much focused dissemination effort has been undertaken. The industrial audiences addressed are the main customers and users of such technologies. Aside for the industrial exposure there were also several scientific publications and presentations to conferences.
Potential Impact:
The results indicate that some of the technologies have reached a maturity level that will allow their immediate exploitation while some other key technologies need further work. Critical issues may hamper initial exploitation estimates and their introduction into a “smart” tooling in the immediate future. It is recommended that a holistic approach be followed for the introduction and integration of technologies in the “smart” tooling.
The project output consists of a set of technologies around the design, manufacturing and operation of innovative process tooling for composite materials manufacturing. The project deals with creation of knowledge on innovative heating and thermal management methods for the smart tooling, robust surface treatment formulations for the tooling, the implementation of (tool-integrated) process sensing, actuation and control in its operation, the organisation of various design aspects around the tooling functionalities and, finally, the integration and demonstration of the tooling operation.
The impact to the competitiveness for the EU moulding industry arises from the fact that the novel technologies may offer:
• Moulds at a competitive price
Outcome: Composite moulds are at a higher price range to that of conventional moulds
Prognosis: Reducing machining costs would effectively lead to reduced mould fabrication costs by at least 20-30% compared to a metal mould for the same level of production (price reduction).
• A reduction on labour intensive operations (to cover the lower labour cost of other com-petitors)
Outcome: This has not been verified yet in the project. Possible automation in the layup and integration of technologies is required.
Prognosis: Need automation in the tool manufacturing process that takes into account the technological add-ons in the design and integration activities. If this is successfully implemented an additional cost savings of 15-20% may be achieved.
• Knowledge intensive-high quality moulds (to counter the USA possible growth in the sec-tor)
Outcome: The project’s results indicate that this could be achieved
Prognosis: Such a product could be furnished in the short-term (1 year from now) if the technological stoppers identified could be resolved.
• Energy savings in the production process
Outcome: The thermal management systems, the embedded heating, the cure monitoring and possibly the efficient control in the future will definitely lead to energy savings. In its current state the work also demonstrates energy savings.
Prognosis: The embedded mould heating system in conjunction with the heat management system and the lower thermal capacity of the mould material may effectively reduce the energy consumption for part manufacturing up to 10-20%.
• Savings in faulty parts/scrap
Outcome: The monitoring process could be used to reduction of faulty parts. Better ma-terial state models are in need.
Prognosis: A reduction of faulty parts/scrap of 15% has been demonstrated in industrial applications
It is seen that despite the efforts and improvements of the technological add-ons key issues still need further action (surface coatings and control). However, in all other areas the issues remain under control or have been resolved in their entirety. The SWOT analysis of the final results are rather encouraging. Furthermore, the priority intervention (i.e. a measure of needed revisit of key technological issues) level has been decreased in most of the technologies. This indicates that after the 18M check point the effort spent has led to improvements and better understanding of the technologies involved. However, certain areas still need further work and some of them they may entail technological risks. In any case the technologies already available are a step further towards the “smart” tooling implementation and such key features may be incorporated in the immediate future.
The potential of the technological exploitation of results has been mapped out in terms of technological readiness level (intervention priority) and risk. The comparison for the developments was made between the 18M check point and the final status. The analysis indicate that certain technologies (thermal management system, cure monitoring, tool construction methods) could be of immediate exploitation while others (actuators for resin infiltration, demoulding) could be introduced without much effort. The exploitation potential of the coating/surface finish for the RTM tool needs further validation before its commercial exploitation while cure based control shows promising results at the simulation level.
List of Websites:
www.coeus-titan.eu
