Community Research and Development Information Service - CORDIS

FP7

ALIVE Report Summary

Project ID: 314234
Funded under: FP7-NMP
Country: Germany

Final Report Summary - ALIVE (Advanced High Volume Affordable Lightweighting for Future Electric Vehicles)

Executive Summary:
The ALIVE project (Advanced High Volume Affordable Lightweighting for Future Electric Vehicles) run from 2012 to 2016 with the aim to develop key vehicle lightweighting technologies based on advanced metal and hybrid materials. ALIVE intends to apply its developments to near-future electric vehicles (EV) to be introduced into the market from 2020 and at a level of technology readiness that would enable mass production.

Affordable weight reduction is one key factor for a more intensive market introduction of electric vehicles. For an EV with 200km range (and with battery capacity of 200–300Wh/kg) the allowable costs of weight saving would be round 8€/kg saved (= 10$/kg saved). For this cost level, more than 40% of lightweighting seems to be obtainable. However, further weight reduction leads to an exponential cost increase. The key objective of ALIVE is to achieve a significant reduction in the weight of electric cars destined for mass production with minimal additional costs. Specifically it is targeting a 45-50% weight reduction of the Body-in-White (BiW) comparing to benchmark state-of-the-art EVs recently introduced to the market, as well as a 25-30% weight saving in the hang-on parts, chassis and main interior sub-systems.

The design, simulation and optimisation phase for multi-material design gave plenty of challenges, due to its complexity both in terms of achieving crash safety requirements, as well as in terms of striking a balance between a series manufacturing technologies and prototyping technologies. The final design of the demonstrator vehicle is a multi-material approach using novel HSS and aluminium grades, together with cost effective fibre reinforced plastic for the roof and battery housing concepts and the lightweight doors (both front and rear) as an advanced multi-material concept. New technologies have been developed and selected, e.g. in-situ casting of the front sub-frame including CFRP and extruded aluminium profiles or the semi-hot formed upper C-pillar node.

ALIVE has achieved relevant weight improvements for the 4 modules targeted (BiW, chassis, hang-on parts, interiors). Most relevant is in the BiW, with a final weight of 229 kg (35% improvement), while the other modules ranged between 15-55% weight reduction. Even though did not reach the ambitious initial targets, safety, cost efficiency and applicability of solutions were prioritised. The results are very positively welcomed by the industry and especially the participating OEMs.

The project has been presented in the most relevant events, including EUCAR, EVS, TRA and the AEBD. The final joint SEAM workshop in September 2016, during the Aachen Engineering Body Days celebrated the conclusion of ALIVE and the SEAM cluster. The event, which gathered partners from the ALIVE, ENLIGHT and EPSILON projects, also counted on the presence of the EC Project Officer, Mr. Maurizio Maggiore, as well as other industry experts.

Project Context and Objectives:
Overall project objectives
ALIVE aims to develop key vehicle lightweighting technologies for application to near-future electric vehicles to be introduced into the market from 2020 up to a level of technology readiness that would enable mass production (around 1000 vehicles / day). The key objective is to achieve affordable solutions for vehicle weight reduction (around €15k selling price excluding battery or €20-25k including battery) targeting a further 20% weight reduction of the Body-in-White (BiW) compared to the 30% weight reduction already demonstrated in recent EU funded RTD projects, with respect to benchmark state-of-the–art EVs recently introduced to the market, while achieving also substantial weight savings with the hang-on parts, chassis and main interior sub-systems.
WP1 objectives
The objective of WP1 is to design a weight-optimized structural electric vehicle including BiW, chassis, heavy interior and closures, based on an architecture sourced from either the ELVA project or the E-Light project, or on an architecture that is a combination of such ELVA/E-Light sourced architectures. The work covers very high levels of functional integration (battery case into floor structure, heating / cooling channels into chassis or BiW parts, interior heavy parts with floor parts. Furthermore the work takes into account the need to offer above five-star NCAP (European New Car Assessment Programme) safety performance (as expected to be required by 2020). The task is not a straightforward design of one fit-for-purpose design solution; rather it is a broad exploration of materials combinations, functional combinations and other lightweighting approaches that can help achieve the highly ambitious weight-saving objective. The design will include a full specification of used materials for each part as well as of joining technologies.

The work is guided by the need to allow for modular build-up of parts to accommodate different drivetrains, battery capacities and interior / upper structure concepts using as a reference criterion a production volume of approx. 1000 units per day. The weight reduction will be achieved by combinations of the advanced materials being applied, innovative functional integrations being adopted and conceived, and novel component designs that are intrinsically lower weight (for example, thinner seats which allow for reducing the overall length of the vehicle while maintaining passenger space and comfort).

The approach is divided into several main steps that are common for each area of the vehicle:
Firstly the architecture & design targets are established (by screening e-LIGHT and ELVA architectures and from those explore new vehicle architectures). Next, the weight targets for this architecture are set and allocated to each submodule, at a level of at least -20% compared to an SLC-level of technology being applied to this adopted architecture. This is expected to be -45% compared to the current SotA EVs (eg. Nissan Leaf). Then the entire design team will agree upon performance requirements for each of the parts in the structural vehicle (static & dynamic stiffness and strength, crash performance, NVH, cost, surface qualities, corrosion resistance, etc. Subsequently each module team will start the design of components & sub-systems of BiW, chassis, hang-on parts and interior with first approaches, thus generating geometries, and initial materials choices. Materials data is sourced from suppliers with regard to existing materials and from WP3 and WP4 for the novel materials developed in WP3. With those geometries and materials data an initial overall vehicle evaluation (NVH, crash) is executed, followed by a multi-attribute optimisation of the BiW concept (application of sensitivity mapping methods). Once this has been completed, a second round of optimizing geometries and (combinations of) materials takes place, followed by a final overall vehicle evaluation (NVH, crash) which then leads to last optimizations and then to a freeze of final design to be prototyped (virtually tested)

In all steps specific requirements/demands for EV such as range, crash and thermal management will be considered. Through this process the Design Lead Team together with all other WP1 partners will define the final content of the concept in terms of materials’ mix and parts’ geometries (supported by material and technology experts) ensuring that the BiW concept fulfils the objectives such as the optimisation of weight, crash, stiffness / static, NVH, cost, manufacturing / assembly and also durability/ fatigue for most relevant parts.
WP2 objectives
The principal aim of these activities to be conducted in this work package is the virtual performance assessment and validation of the vehicle design options developed in WP1. As such WP2 and WP1 will be conducted in parallel and essentially constitute the two fundamental stages required in the definition of a validated design solution while drawing on the information concerning the selection of advanced materials and the definition of manufacturing processes which are the aims of WP3 and 4 respectively.
The virtual performance assessment activities to be performed in WP2 will involve numerical simulations using a range of state-of-the-art tools and methodologies including:

• Multi Body Simulation (MBS) for numerical loads generation (local loads for components used for strength and fatigue evaluation as well as for testing),
• Finite-element (FE) analysis to determine the quasi-static, dynamic and modal behaviour of flexible components
• Non-linear FE for crash analysis
• Statistical Energy Analysis (SEA) to assess the acoustic performance
Furthermore a holistic simulation methodology will be developed to enable the implementation of the various design concepts, materials and manufacturing technologies into one simulation environment in such a way that it can be used for vehicle dynamics, fatigue, crash and NVH purposes, representing a leap in terms of simulation efficiency.

The approach to be adopted will cover the following aspects in respective tasks:
• Material models including multi-material systems: Developing appropriate, reliable and accurate material models for advanced materials such as ultra-high-strength steels, Al and Mg alloys, and in particular FRPs for which representative models still do not exist in most simulation environments;
• Models for joining technologies: Representing the combination of dissimilar materials e.g. FRP and Al for which conventional joining techniques such as welding are not applicable;
• Development of a holistic simulation environment: Implementing the various design concepts, materials and manufacturing technologies into one simulation environment;
• Validation of simulation environment: Calibrating the numerical models through comparison with measured experimental data;
• Performance assessment on component and sub-system level: Supporting the design and the optimization of sub-groups at sub-system level;
• Full scale vehicle simulation on all attributes: Determining the vehicle performance on the full-scale level with respect to all relevant attributes.
WP3 objectives
The main objective of this project is to reduce the structural weight of the body-in-white (BiW), chassis and heavier interior by using different classes of materials: light alloys, composites, polymers, advanced steels and multi-functional materials and the application of their manufacturing processes: forming and joining technologies, cost-effective assembly and modularity.

To realise this task, we would have to adapt selected material classes; to develop manufacturing, joining and bonding technologies; to characterize the materials by using those technologies and, finally, to realise manufacturing and assembly strategies.

WP4 objectives
WP4 is the central work package for testing, characterisation and validation within ALIVE. The testing and validation will be performed on coupon level, sub-system level and on vehicle level introducing advanced test strategies for accelerated testing. Attributes considered are static and dynamic properties of materials, components and sub-systems, fatigue behaviour under defined environments as well as crash and NVH properties.

All test specimen, components or sub-systems will be delivered from other work packages. The test program (e.g. attributes to considered, environmental conditions, load program) will be defined together with all OEMs and suppliers involved taking into account concepts for accelerated testing.

In order to validate the material and simulation models (WP2) as well as the material and manufacturing technologies, coupon tests will be performed. This will be done as benchmarks by defined partners only to obtain reproducible and reliable data. The measurements on coupons will be fed back to WP2 and WP3 for validation purposes and optimisation. With respect to WP3, coupon testing will be performed for different stages of the development process (iteratively).

Testing and validation on sub-system and vehicle level will be done on limited number of demonstration parts to assess e.g. the fatigue strength, crash and NVH behaviour. The parts to be tested will be provided by WP5.
WP5 objectives
Deliver realistic experimental validation modules that allow for static, dynamic and crash performance validation on the module level (see task description T4.4). Combining each of these modules into a full vehicle demonstrator, representing lightweight technologies focusing on the four main weight determining structural areas of the EV: heavy interior, body-in-white, chassis and hang-on-parts.

The demonstrator build-up is split into several levels and phases. Initially and in parallel to the design and optimisation loops in WP1, the work in WP5 focuses on the identification of realistic yet cost effective production routes for all structural parts and their joining processes. Gradually in WP1 the design of components will be frozen and released to WP5, which then starts the mould design and prepares for component production. The WP5 will deliver duplicates of some of the smaller modules to allow WP4 to perform various very realistic tests. On top of these modules destined at partially destructive testing, one full structural demonstrator will also be assembled that will allow for non-destructive testing on the whole vehicle level.
WP6 objectives
The goal of WP6 is the generation of appropriate and reliable LCA models for the new ALIVE materials and production technologies and an easy-to-use assessment of design alternatives. Therefore, data on the materials themselves, their production and the manufacturing of automotive parts out of these materials has to be analysed from an environmental perspective with respect to:
• High-strength steel
• Aluminium alloys
• Magnesium alloys and
• Innovative composite materials
Detailed data will be supplied by the project partners via questionnaires. The material production and the manufacturing of parts will then be modelled in the LCA software "GaBi". In an interaction step, the results will be discussed with the project partners to emphasize the most relevant steps in the production from an environmental perspective by applying an easy-to-use web-based tool (GaBi i-report). It will enable the partners to understand the most critical steps in production and give them indication, where the production should be improved or even a switch to another material is indicated to improve environmental friendliness. To avoid "shifting of burdens" meaning e.g. that a material or production process is improved but then maybe lead to higher environmental impacts in the utilization or recycling phase, it is important to consider the whole life cycle of an automobile. Therefore, beside production of materials and manufacturing of parts, we will consider the automobiles utilization phase. We will also include the automobiles end-of-live.

To carry out the LCA assessment in WP6, information is collected from the project partners about related issues. The information we will need to carry out WP6 is collected by questionnaire that will ask about material compositions of the ALIVE materials and energy use, emissions, yield used materials and auxiliaries for the production of parts. The effort per partner to fill in the questionnaire is not budgeted separately here in WP6 but rather is made inside WP1 and WP3 by all relevant partners.

The ALIVE technologies will be modelled in the software system "GaBi". GaBi contains the world’s largest life cycle inventory library based on industry data and is therefore ideally placed to leverage our extensive knowledge of processes and materials to devise the specific datasets required for ALIVE technologies. Within the project, we can build on this data to efficiently model the technologies and materials under consideration. So we do not have to start from "nothing" but concentrate on the new innovative materials and technologies in ALIVE and ensuring efficient and reliable LCA datasets with a suitable effort.

LCA data in LCA software tools is usually not self-explanatory. Typically, LCA experts are required to interpret data and derive design requirements out of it. To enable project partners to assess and optimize the environmental impacts properly, we will apply a web-based tool, the "GaBi I-report". This tool combines the whole LCA know-how with an easy-to-use web interface. The GaBi i-report has the full LCA models and data in the background but allows the user to work with pre-defined scenarios to assess the effects of design changes immediately, considering of course the whole life cycle of an automobile. If, for example, a new innovative material is applied, which has higher efforts in the production but then due to a lower weight, big advantages in the utilization phase and/or recycling, designers will be able to see results immediately.

The assessment of environmental issues will be expressed by so called "environmental impact categories". Those aggregate the huge amount of emissions, energy or resources consumptions into a few meaningful numbers. Examples include the following:
• Primary energy demand (which is strictly speaking not an impact category, but anyway relevant)
• Greenhouse gas emissions
• Abiotic resource depletion
WP7 objectives
WP7 will communicate the ALIVE objectives and results to a wide range of target groups, making use of a set of target-group adapted and tailor-made communication tools. Due to the importance of this spread of knowledge, all ALIVE partners are involved in this work.

The overall aim is to spread the project findings to a wider group of industry actors, from the transport and materials sector, to public actors, in particular research organisations and academia, and the wider public. Dissemination approaches, target groups and communication tools will be described in detail in the ALIVE communication and dissemination strategy that will be developed at the beginning of the project.

Furthermore, this work package will ensure to extrapolate the results generated mainly on the basis of passenger cars also to other material applications. In particular this will be targeted to heavy vehicles such as trucks and buses. This work package will also deliver a first plan for industrialisation of the materials, products and processes developed.

WP8 and WP9 are the management and coordination WPs and are summarised in a separate section.

Project Results:
Summary

The first preliminary crash simulation (EuroNCAP ODB) showed a poor behaviour of the structure. As a consequence, an optimization process resulting in a redesign followed: aluminium alloy cast nodes were redesigned or substituted by high strength steel parts; the sub-frame and its connection to the bottom area was redesigned; the buckling behaviour of the front longitudinal members was improved; and the C-pillar area was also redesigned to improve static bending and torsional stiffness. Simulation work was divided into 3 focus areas in order to facilitate the optimization process: front crash behaviour, side impact cases and rear crash case.

The table below provides an overview of the weight estimations in the final design freeze compared to the weight achieved in MS1, as well as the reference and targets defined. As further explained in the subsequent tasks, it is important to highlight that the overall reference vehicle adopted is the one designed in the ELVA project with some minor modifications (from now on referred as ELVA modified).

Relevant improvements have been achieved in all the sub-modules, with some of them clearly exceeding the target set. Specifically on the BiW, though, it was not possible to achieve the stringent target at design freeze, due to the need to design a structure compliant with crash demanding requirements. Some relevant re-design activities had to be undertaken after design freeze:

1) Design of BiW as lightweight design for high volume series production with appropriate production technology and tooling.

2) Redesign of parts that cause high tooling costs (deep drawing parts) for “easy to manufacture parts”, e.g. metal sheet bending parts.

3) Redesign of structure to be able to use existing parts as carry over parts (cop), e.g. side panels for both left and right hand side (tooling for one side panel costs several hundred thousand Euro).

More details on the major S&T results achieved are provided below specifically per each WP.

WP1

The ALIVE project is focusing on affordable lightweight design for vehicles produced in high-volume production (1000 vehicles per day). In the deliverables 1.1 till 1.2 all necessary specifications and requirements are described. Main objective is a target weight of the body-in-white of 200 kg (including the battery case), which fulfils the safety requirements concerning the crash scenario’s described in WP2 (following chapter).

The final design of the ALIVE BiW fulfils all crash and stiffness requirements; however, the weight target of 200 Kg could not be accomplished. The weight of the BiW is now 229 Kg which is 14% higher than targeted. But in the view of the coordinator this is still a good result, e.g. comparing this to weights of BiW’s of actual series production vehicles.

The design of the BiW is a multi-material approach using high strength steel and aluminium grades. In addition cost effective fibre reinforced plastic was applied. This caused the application of various and sometimes not well established joining technologies. The consortium developed a common assembly strategy which allows to manufacture the demonstrator BiW’s with the quality necessary to not only present a structure but to conduct destructive testing, too.

The front body concept is designed with three loadpathes to lead crash loads into A-Pillar, sill and foot well cross member. It consists of high strength Longitudinal Member of hot formed steel, a front structure of Aluminium and a Cross member Subframe of die-casted and extrusion Aluminum. The Strut rings are made of Magnesium.
Upper body consists mainly of Aluminum sheets and extrusion profiles. A-pillar and B-pillar are made of hot formed high strength steel (RM > 1800 Mpa). By this the wall thickness could be reduced from 2 mm to 1.8 mm which led to a weight reduction of 1.9 kg.

CRF developed two concepts for the roof made of fiber reinforced plastic. Further details of design can be found in the following chapter WP2. The FRP roof is bonded to the body in white by gluing.

To integrate the battery case an innovative concept was found: the Battery-Cover-Plate made of Thermoplastic GFRP has integrated Fixing Elements for the Seat Rails. Bracings from Bottom and the Cover-Plate with bolts close simultaneously the electrical connections. Aluminum Cross members with Deformation Elements for Crash Protection and to stiffen the BIW form the battery case. By Intrusion of the Sill the Battery-Cover will moved but not be damaged.

The doors have been designed as Aluminum concept, Fig... The front door shows three load paths and consists of 13 components, mainly 5000 and 6000 Aluminum alloys. The weight target could be achieved with a weight status of 9.5 kg. The rear door with two load paths consist of 12 components with similar Aluminum distribution. The inner sheet panel is laser welded as one part. Status weight is 5.4 kg, target was 6.2 kg. A higher weight reduction of 13% could be achieved.

WP2

Principal aim of the simulation activities of WP2 was the virtual performance assessment and validation of the vehicle design options developed within the project (in WP1).
This was done for the concerned vehicle solutions, on component and sub-system level, as well as on full-scale level, w.r.t. all relevant disciplines/attributes, which means crash, static, NVH and fatigue analyses.
Before entering the above mentioned assessment phases, preparatory activities were needed and developed within the WP, i.e.:

- generation of model cards for the advanced materials selected on ALIVE vehicle;
- development of models for the involved joining technologies (RSW, MIG, FDS and Adhesives);
- set up of a holistic simulation environment, permitting the integrated and centralized management of the numerical models required by the different simulation disciplines.

The created numerical models were indeed validated, through dedicated experimental testing at coupon level, by considering specimens representing the combinations material/joining technique used on ALIVE vehicle.

Moreover, the operational use of the holistic simulation environment demonstrated the possibility to accomplish relevant timesavings in model preparation phases (40 to 70 % less w.r.t. classical «manual» approach).

The performance assessment task on sub-system level involved mainly 3 vehicle modules, namely composite roof, chassis subframe and front doors.

Composite roof design was driven by roof crush strength (FMVSS 216 a) and side pole impact (FMVSS 214) standards, with static torsional, flexural and modal analyses taken into account, too.

An hybrid solution was selected at the end for the realization of the final ALIVE roof prototypes, consisting of a sandwich structure and glued aluminum cross-members (two 0.5 mm thick thermoplastic GFRP laminates with an internal pressure stable polyester nonwoven core of 3 mm). Chassis subframe final design originated instead from several evolutionary steps applied to a previous structural concept taken from the past EC project ELVA: through static and dynamic analysis on the isolated subframe, adequate stiffness’s of suspension lower control arm attachments were pursued in order to ensure good handling and avoidance of vibrational problems at full vehicle level.

Front door design was optimized by considering different evolutionary steps, each one being evaluated against 6 main load cases: door sagging & over opening, cross member & window frame stiffness, outer panel oil canning and door global eigenfrequencies.

Full-scale vehicle simulations were conducted to assess the adopted solutions w.r.t. agreed reference targets for each attribute, according to the vehicle design evolutionary loops: for the crash performance assessment, front and side Euro-NCAP current impact configurations (ODB, FWRB, AE-MDB and Pole) plus FMVSS 301 rear collision were considered.

Manufacturing data coming from process simulations were included on vehicle crash model, too, for the final design verification.

Static stiffness performance assessment (in bending and torsion classic BiW tests set-up), structural dynamics and NVH analyses (free-free modes of BiW with added masses of each relevant vehicle sub-system) and fatigue analysis (w.r.t. reference loading events, i.e. bad road, handling test course, load change shock and race course, each one with its own duration and number of repetitions) completed the assessment on the final solution.

Structural performance targets fixed for each relevant discipline were almost entirely achieved with the final vehicle design: in few cases exceptions were accepted because of the limited deviations and/or the possibility to manage them through other classical vehicle systems/solutions (not included within ALIVE perimeter, like for example side airbags).

WP3

Main objective of this WP was to provide state of the art materials, to adapt selected materials and to develop new materials especially for the use in the ALIVE project, to reduce the structural weight of the body-in-white, chassis and heavier interior parts. For the application of these materials, it was required to develop the manufacturing, the joining and bonding technologies, to characterize the materials by using those technologies and finally to realise manufacturing and assembly strategies.

During the project, the materials database started in the first period has been updated with more material data. The database was at the end filled with material data of about 100 different materials (steel, aluminium, magnesium and plastics). This document represents a useful synergy and joint development within the SEAM cluster and between the ALIVE and ENLIGHT projects, so that both projects were able use the parameters from the material database. Whereas ALIVE provided all information and data for the metals and some plastic parameters, ENLIGHT completed the database with information for plastics, fibres and resins and also fibre reinforced plastics.

Together with WP1 materials for all components had been selected and validated by forming simulations, crash calculations and joining possibilities. This was done in several iteration loops as long as the selected material fitted best to the requirements and targets of the project.

The main activities of task T3.1 were to provide full materials data to WP1 and WP2 for the ready developed materials by adding this data to the material database, the development and basic characterisation of AHSS steel grades of 3rd generation with improved formability and to develop and characterize a press-hardening steel grade with a tensile strength of 1800 MP and to perform forming experiments for the steel grades foreseen for the use in the ALIVE vehicle.

Forming of AHSS with improved formability
AHSS of 3rd generation (so called ahss high-ductility or HD grades) have a significantly better formability than the conventional and already well known AHSS of 1st generation (ahss classic). This is noticeable especially in the total elongation A80, the work hardening (n-value) and the forming limit curve (FLC). In the figure below the minimum guaranteed total elongations (A80 according to ISO 6892-1) are shown for selected HD grades (compared to the respective conventional grades). Here, the differences between conventional and HD quality are very clearly recognizable.

Forming experiments with “Smiley” – tool
The trials with the model tool “smiley” were carried out on a 630to press with a blank holder force of 900 kN. With this tool four embossments can be stamped in different shape and depth into the part. The blanks were oiled with 1.5 g/m² PL61 to ensure the comparability of the single experiments. The formability was evaluated at the critical regions (see both figures below) for different AHSS of 1st and 3rd generation. Based on the results (see fig. 77 and fig. 78 below) the improved performance of the HD qualities can be shown with this tool.

During the ALIVE project all planned steel grades were brought at least to a pilot production and material for part production was delivered to the partners.
The following paragraphs describe the actual status of the material development, their properties and availability of the AHSS and UHSS grades.
All usual AHSS and UHSS grades of 1st generation up to 1180 MPa (and even conventional grades according to VDA 239-100) were already available at the beginning of the project.
Regarding the AHSS of 3rd generation with improved formability various grades have been developed. These are also cold-formable grades with tensile strengths up to 1180 MPa. The focus here is on the dual phase high ductility grades for complex components but also complex phase high ductility grades were considered. After a period of lab scale sample productions several large-scale productions were carried out with good results for e.g. DP780HD, DP980HD, DP1180HD und CP1180HD. The target values for the mechanical properties (yield strength, tensile strength and in particular the total elongation) could be reached and the sample characterisation was finished.
To show the improved elongation and better formability forming experiments with model tools were performed.

For the press-hardened steels the indirect process with phs-ultraform 490, phs-ultraform 1500 and also tailored properties is already state of the art. To extend the family of press-hardened steels a grade with tensile strength of 1800 MPa in press-hardened condition has been developed. During the ALIVE project the highest strength grade phs-ultraform 1800 were produced in a pilot production with the needed thicknesses for parts production.
The actual status of hot forming steel grades is shown in the following table.

As all defined steel grades are now available at least in a pilot production status voestalpine were ready for supplying the ALIVE partners with the needed steel material for the prototype production.
Based on the material selection in cooperation with design (WP1) and simulation (WP2) voestalpine supported the defined part producer with the steel grades for the ALIVE body.

In task T3.5 to accomplish the main goal expected in the ALIVE Project, i.e. to obtain an electric vehicle achieving affordable solutions for weight reduction, CIDAUT has worked into the development of a new casting process for the production of automotive components with high requirements by means of the use of magnesium alloys. A series of stages that included: process design, process prototyping and testing at CIDAUT’s premises were done to accomplish this goal.

Magnesium alloys have the main advantage that they are the lightest of the used metal alloys, one-quarter the mass of steel and two-thirds the mass of aluminium, and have the best strength to weight ratio of the most commonly used structural metals.

Moreover, the advantage of the new process is that we have solved the main drawbacks that the magnesium casting processes presents:
- Sand casting: it is a process with a low production rate and a high melt oxidation due to a turbulent filling
- High pressure die casting: it is a high volume series production, but with high problems with gas porosity due to the high velocities produced during filling

With the new magnesium technology developed by CIDAUT these drawbacks have been avoided when compared to magnesium current casting technologies. The main characteristic of the process is the use of an electromagnetic pump to impulse the molten magnesium inside the sand mould. A counter-gravity and controlled filling is possible with this device, which implies no turbulences during the filling stage, and as a conclusion no oxides or gas porosity are present in the final parts.
Furthermore, some metallurgical techniques have been accomplished with treating magnesium alloys with grain refiners to improve final microstructure. Refinement and modification treatments would be applied to molten magnesium and thus improve the quality requirements expected.

Additionally this technology has the advantage that it is possible to manufacture high magnesium performance components with a low cost technology, mainly due to low tooling costs and due to its high productivity (due to the automatic sand moulding process).

Task T3.6 was particularly relevant with the development and assessment of the joining sequence. Looking at the assembly process it becomes clear, that especially the joining processes between the steel front corner assemblies and the aluminium assemblies’ bulkhead and central floor were the most challenging. Further on the assembly process between the large aluminium assemblies like the rear wheel housing and the rear end were also particularly challenging concerning the tolerance chain.

WP4

The main objectives of the work performed in this WP4 was to determine the characteristics of different lightweight materials and different joining technologies regarding crash, fatigue and NVH behaviour. Therefore test on different specimen, components, subsystems and finally the BiW were performed.

Test strategies for accelerated testing
At the start the test scenarios and test conditions especially of coupon tests were developed in order to provide sensible results for the modelling for the crash, fatigue and NVH calculations. Subsystem and BiW test scenarios were developed to provide data for the validation of the numerical models and to confirm the overall lightweight potential of the ALIVE prototype. To optimise the fatigue testing strategies for an accelerated testing were developed by sophisticated high frequency test rigs and methods to accelerate multiaxial testing by deviation but damage equivalent load programs also including environmental test conditions. As a result for the multiaxial fatigue testing with numerical calculations to optimise the number of repetitions of the different load signals a damage equivalent and shortened load program can be derived. In reality this will mean to allow for some deviations and, in case of the multiaxial shaker testing, to perform some additional measurement bevor the testing.

Characterisation and testing of coupons
Coupon test of the various materials and manufacturing technologies were carried out to provide feedback and information to especially WP2 focussing on providing material model parameter information and joint model parameter information. Furthermore the holistic simulation environment developed also in WP2 is validated making use of measurement results generated. Various novel metallic materials are tested according to their fatigue, tensile and NVH behaviour, as well as a number of different joining techniques.
Materials and joining techniques tested have been selected in close discussion with mainly WP1 and WP2 partners.

Materials under test:
• Press hardened steels: phs-ultraform 1500 and phs-ultraform 1800
• AHSS high ductility: CR900Y1180T-DH (DP1180 HD) and CR440Y780T-DH (DP780 HD)
• Aluminium 6016-T4 and 6082-T6
• Magnesium
Joining techniques under test:
• Flow drill screwing (FDS)
• Resistance spot welding (RSW)
• MIG welding
• Bonding
Attributes tested:
• Strain controlled fatigue
• Static/dynamic tensile behaviour
• Dynamic NVH behaviour

Deliverable 4.3 comprises a very detailed reporting on test procedures adopted and test results obtained. Furthermore, parameters were identified/extracted to feed into the numerical models.

Testing and characterisation on sub-system level
Components and subsystems which were build using the materials and joining technologies investigated before were tested under crash and fatigue. In order to determine the salient performance characteristics of the new, lightweight components and sub-systems developed within the project, the experimental analysis also has focused on identifying their principal dynamic properties, in particular the stiffness (through FRF measurements or crash deformation) and modal damping characteristics.

As one of the tested materials Aluminum has been widely used in automotive industry since 2000 but the current trend is to exploit a multi material strategy in order to define the right placing of the different materials. Some enablers of this approach are promising technologies for joining steel and Al that have been tested. The most promising seems to be the FDS (Flow Drilling Screw) with respect to RIVTAC technology.

Aluminum parts with new materials have to be tested carefully for strength and durability as the new lightweight approach needs to be feasible for all the performances and the results are encouraging from many point of views. Some corrections are maybe needed but the benefit in terms of weight saving and the overall good performances are good news for the new vehicle design. But steel is not a material to forget. The recent studies and enhancements of performances for Advanced High Strength Steel witness a renewed interest on new trade off for this material. The work on B pillar and hat profile are there to show the progress of the new steel materials. Moreover tailored blanks or laser welding are enlarging the mixing of different steel material grades. Composite parts are increasing their relevance on the vehicle and the roof of the ALIVE vehicle shows a good compromise with respect to a steel roof. The same overall behavior of the BIW is really closed to current production global modes.

Full vehicle testing and validation
The BiW was finally tested regarding to NVH, crash and fatigue characteristics. Testing with different load sequences with respect to dynamic properties and durability was done for the front section of the BiW on a multiaxial shaker table. The focus was to measure the transfer functions between accelerations and local strains to verify the proposed methods for the accelerations of this kind of testing.

Summarising testing with different load sequences with respect to dynamic properties and fatigue was done for the front section of the BiW on the MAST. The focus was to measure the transfer functions between accelerations and local strains to verify the proposed methods for the accelerations of this kind of testing. It became obvious that an approach to evaluate local fatigue only on the acceleration input signals of the test rig is not sufficient. A sensible approach to reduce test time is to measure the transfer functions between the accelerations at different points of the system and local strains at the hotspots. These transfer functions differ for different frequency areas. With these functions it is possible to calculate the impact of a change of the load input accelerations (scaling of acceleration values, increasing of frequencies, cutting of sections out of the load-time histories - omission) on the damage content for the different sections of the test sample.

Additional tests under crash loads were performed using crash test facilities. The results were mainly used to validate the results of the numerical based crash calculations of task 2.6. As real life crash tests a front impact against a rigid barrier (according to Euro NCAP), a side pole impact (according to Euro NCAP) and a modified rear impact (related to FMVSS301) were performed.

It can be concluded, that a good correlation is achieved in the frontal crash scenario. The main effects are modelled and are comprehensible. Main divergences between the base model simulation results and the test results are based on not expected failure in the main front long member material. Also the designed connection between upper long member and shotgun was too weak. Further differences occur in the behaviour of the tyre model. The tyres in the simulation behave a lot more elastic. This can be explained by a closed air volume of the tyre model. A detailed model of the tyres was not foreseen in the frame of the project. The main effects are adapted in the validated model and the performance is confirmed.

Furthermore the BiW was tested regarding to NVH. The test setup consists of a BiW with and without doors suspended by 4 air springs placed at the side skirt to create a free-free boundary condition and excited by 2 shakers with uncorrelated random signals. The main focus of this work is to validate the numerical results obtained within the work of task 2.6.

The NVH studies performed and results obtained within the framework of this deliverable suggest that the model of the BiW without attachments used in deliverable D2.6 is in good agreement with the physically built BiW. This conclusion is drawn from the comparison of a simulated and an experimental modal analysis of this BiW.

From all these investigations it can be inferred that the chosen materials mix and its application to the mass market production are not unfeasible and only minor modifications are needed to fully withstand with complex vehicle specifications that are currently set by the design department of the OEMs.
WP5

Magna was defined to build up one demonstrator vehicle including the doors and closures, the chassis and the driver´s seat. During the project from simulation side the demand came up to test physical bodies or modules (frontend, rear-end) to evaluate the simulation results. Due to this fact a frontend module and a rear-end module and an additional complete body were built to evaluate the simulation results. They were delivered to the institutes involved in testing.

Before making the prototypes and the demonstrator Magna was involved in defining and optimizing the assembly sequences together with Benteler. This work was basis to be able to produce all the needed modules with the defined budget and within the timeframe.
Magna also gave its input regarding joining techniques and made some sample testing with spot welded aluminum sheets.

Jigs and devices based on the released design were developed and produced. Regarding the welding seams in the floor area of the body, it was necessary to produce a turntable to rotate the complete body upside down. It is forbidden to weld aluminum overhead because of the danger of molten material falling onto the worker, on the one hand, and poor welding seam quality on the other.

The bodies and modules were produced on a measuring plate. That is the standard method for producing bodies with a very limited edition to be cost efficient. Planning the prototype production we saw that one challenge is the schedule and we had to produce in two shifts.
That is unusual because we had to teach two teams and handing over the data from one team to the other was very important.

Finally the project gave us the chance to extend our know how in multi material application regarding joining and prototyping. Following slides show a photo documentation of prototyping the body-in-white demonstrators PT1 and PT2 for testing in work package WP4.

Demonstrator of hang-on parts (assemblies)
The components of both the front and rear doors are shown in Fig.27. Except the impact beam all components are made of 5000 or 6000 aluminium alloys. They are formed at room temperature. The one-piece inner panel of the front door uses a tailored welded blank of 2.0/1.2 mm. It is cold formed with only one mould. In a series manufacturing process two moulds will be used to achieve better quality. The impact beam of 7000 alloy can only be formed at elevated temperature. The forming process is developed in a cooperation between Daimler, AMAG and Magna.

The aluminium components are joined together by adhesive and rivets, remote laser welding, spot welding and hemming. The final assemblies are shown in figure below.

The prototype tailgate consists of polymer components (Fig. 29 left). For the prototype a laser sintered frame reinforcement is used. In assembly process adhesive bonding is mainly used. The final prototype can be seen in Fig. 29 right.

WP6

The objective of WP6 is threefold, including assessment of ALIVE materials, the ALIVE vehicle and the set up of a LCA tool for ALIVE vehicle screening.

In a first step WP6 analysed the materials, especially steel, aluminium, magnesium and composite materials used in within the ALIVE project. The results are included in Deliverables D6.1. to D6.6. The materials include the materials in the ALIVE material database, cf. WP3.

Deliverable 6.7 applied the findings to the entire vehicle. The results are shown in the following table.

The analysis revealed a clear benefit of the ALIVE vehicle compared to the reference in all assessed impact categories. Additionally a web based scenario tool has been developed to assess the environmental performance of the ALIVE vehicle during the design phase based on key parameters. An explanation and manual of the tool is provided in D6.8, the login details for the tool are provided in D6.9.

WP7

The overall aim of WP7 was to spread the project findings to a wider group of industrial representatives, from the transport and materials sector, to public actors, and the wider public. Therefore the partners focused on defining the dissemination strategy for SEAM as well as creating the “cluster identity”.

The ALIVE and SEAM dissemination strategy was prepared in coordination with ENLIGHT, Matisse and SafeEV. A logo has been developed for the projects and common templates for deliverables and presentations were provided. An ALIVE brochure was designed and provides general information in a representative manner. The brochure was used to increase the awareness of the project.

A project website was developed and updated regularly with content (www.project-alive.eu). The ALIVE website has accounted for 2.075 visits after project completion, this is translated into a positive average of about 250 visits/month. Additionally, the ALIVE subsection of the SEAM cluster website was set up (www.seamcluster.eu). ALIVE partners have presented the project at relevant external events and conference across Europe. The information about publications and dissemination activities is also available on the ALIVE website in the section results.

The results out of ALIVE are compressed in an educational material module for use in an academic and industrial course.

The SEAM Liaison team established in the 1st period has consisted of the four project coordinators (Jens Meschke, VW – ALIVE; Thilo Bein, LBF –ENLIGHT; Roland Wohlecker, FKA – Matisse; Andreas Teibinger, ViF – SafeEV) and three partner representatives (David Storer, CRF; Christian Sahr, ika; Laszlo Bax, B&W). Aiming at supporting the Liaison team, the SEAM Project Office was also set up, consisting of Thilo Bein from LBF and Harilaos Vasiliadis from B&W.

The main goal of the SEAM PO and Liaison team has been the harmonisation of the developments of the 4 projects, increasing the opportunities to identify synergies and leverage knowledge generated, while broadening the impact of the SEAM cluster dissemination as the largest lightweight initiative in Europe. Some relevant synergies and connections achieved have included:
• Technical integration between projects: e.g. intrusion beam developed in Matisse into ENLIGHT and ALIVE door modules; doors developed in ENLIGHT into ALIVE; front hood developed in ENLIGHT into ALIVE.
• Input provided during the definition of H2020 work programmes for 2016-17, via the European platforms and associations linked to the partners (EUCAR, EARPA, ERTRAC, etc.).
• Utilising partner booths at fairs and tradeshows to disseminate SEAM materials (e.g. JEC Europe to showcase modules developed during the ENLIGH project).

SEAM Cluster newsletter #3, November 2016
Issued after the organisation of the SEAM final event in Aachen, during the AEBD16. The event was a success, counting on the presence of more than 100 attendees during the conferences who generated interesting debates related to project results. Different dissemination audiences targeted in the project also did attend and contribute to the event, including policymakers (European Commission Project Officer Mr. Maurizio Maggiore) and external industrial and research peers form the wider lightweight community. The final plenary session was also wrapped up with a discussion of the importance of lightweight materials in the future of EU automotive sustainability, sharing the vision of the SEAM partners for the short-term future.

More than 200 people were engaged in the joint SEAM mailing list, a critical mass of expert community in Europe on lightweight design of electric vehicles. The engagement statistics can be seen below. They are considered very positive, in comparison with standard expected “conversion rates” for typical newsletters: from 2x to 4x higher engagement.

SEAM Cluster discussion network
In order to strengthen the networking and connections between all SEAM partners, a SEAM discussion group was set up and maintained in the LinkedIn website. It has also served as a platform to discuss developments in the different SEAM projects as well as a framework to share international news outside SEAM, which were relevant to the lightweight community. Some screenshots of the SEAM discussion group in LinkedIn are attached below.

Potential Impact:
Publications and dissemination
ALIVE has published 7 scientific papers (3 expected in 2017) in high-level specialised journals, e.g. ASME Journal of Vibration and Acoustics, as well as in relevant high impact industry magazines and conferences, such as SAE. At the same time, the ALIVE partners has carried out 43 dissemination activities, including both internal dissemination at partners premises, and external actions, presenting the project in the most relevant dedicated conferences in the lightweight and electromobility field: EUCAR, Aachen Engineering Body Days, Transport Research Arena, EEVC Conference or the EV Symposium.

A detailed list including all dissemination actions is annexed below in Section A.

Exploitable results
The ALIVE partners have produced a number of valuable and exploitable results, including:

• Magnesium sand casting technology, by using an electromagnetic pump and an advanced electronic control system.
• Methods to accelerate the fatigue testing of materials and components.
• Numerical fatigue calculations of components and complete BiW by using sophisticated modelling techniques of joints
• Cyclic material characteristics
• New thermoplastic composite roof concept design based on a sandwich structure made of two thin plies of GFRP with a pressure stable polyester nonwoven core

Partner Faurecia has also registered an utility model in Germany related to the developments of ALIVE (adjustment element for an adjustment device of a vehicle seat). More details are annexed in section B below.

Impact
The implementation of ALIVE results into real vehicle developments will contribute to achieve several impacts including:
• Environmental impact – CO2 reduction in Europe due to EV lightwieghting (422.0000 tons of CO2/year) and 9,6 millions tons of CO2/year due to ICE lightweighting. Additionally, reduction of some 2 million tons of CO2/year (rest of the world).
• Impact on urban quality of life and health, including urban quality of life improved, substantial amounts of healthy life years saved.
• Economic impact on EU competitiveness: ALIVE will contribute creating a European competitive advantage in EV vehicle architecture and concept.
• Economic impact supporting to anchor and create jobs in Europe, estimated in total 370.588 jobs (both direct and indirectly related to automotive manufacturing)
• Economic market impact for ALIVE partners, assessed in a business worth €7,5 billions which will supporting them strengthening their position in the global market.

List of Websites:

Website: www.project-alive.eu

Contacts:
Dr. Jens Meschke
Coordinator
VW AG
jens.meschke@volkswagen.de

Related information

Reported by

VOLKSWAGEN AG
Germany
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