Periodic Reporting for period 1 - DEMONSTRATE (DEMonstration Of Novel fuSelage sTructuRAl inTEgrity)
Período documentado: 2021-01-01 hasta 2022-06-30
The objective of the Demonstrate project is to evaluate the structural resistance of two new airframe designs; one in Al-Li alloy and one in thermoplastic.
The Demonstrate project is divided into four specific yet complementary research areas:
• Development of a new virtual test methodology to evaluate the influence of various boundary and loading conditions on curved panels representative of the conditions airframes are subjected to when under flight conditions.
• Development of a novel test bench concept, which is easily adaptable to different geometries, and which allows the required boundary/load conditions to be introduced.
• Study of new metrological techniques to monitor panel deformation and capture damage during the test.
• Development and application of an advanced simulation methodology specific to the materials used in this project (Al-Li alloy and thermoplastic).
In this project Applus+ proposes to develop a test bench for curved fuselage panels that will guarantee:
• The adequate introduction of axial, bending, torsional and shear loads.
• The simulation of internal pressure changes that result from cabin pressurisation and depressurisation.
The Demonstrate project test bench will be suitable for testing a wide variety of large curved panels, of different lengths and curvatures with different load configurations and boundary conditions too.
Due to the variability of curvature radii and beam geometry of the panels, it will be necessary to design a test rig that allows the modularity of its components to be easily adapted to each configuration to ensure full structural certification.
The test rig proposed by the Demonstrate consortium requires only one curved panel segment instead of a complete cylindrical section of the fuselage, allowing new structural concepts and new materials to be validated at a lower cost.
The accuracy of the FEM models used to perform virtual tests can be evaluated by performing laboratory tests, then contrasting the information obtained with the results of the virtual tests.
To this end, this project will implement the Absolute Accurate methodology. This is an experimental approach developed by Applus+ that aims to provide a more robust way of identifying the boundary conditions of the tests performed by extending the instrumentation beyond the sample and monitoring the test bench.
Innovative tools developed by Applus+ will be used to improve the calibration and validation of FEM models.
These software solutions provide a digital infrastructure to facilitate the comparison of experimental test results and simulations, the creation of material charts used in the simulation software and the validation of the simulation model.
As the project aims to improve the quality of results, Digital Image Correlation (DIC) technology will be applied. This allows a faster and more accurate measurement of the deformation field of a structure.
The monitoring of the deformation field will be carried out in real-time thanks to the optimised algorithms of Digital Image Correlation (DIC).
New methods will also be applied to improve the detection of crack/delamination initiation and propagation. To perform the standard non-destructive inspection techniques used to monitor crack initiation, crack evolution (in metallic structures) and damage growth (in composites), the test needs to be stopped, and these inspections have a significant impact on test execution time.
To satisfy all these different requirements and bypass the delays that would be caused if using standard non-destructive inspection techniques, various damage monitoring techniques will be applied which do not require contact.
The Demonstrate project is divided into four specific yet complementary research areas:
• Development of a new virtual test methodology to evaluate the influence of various boundary and loading conditions on curved panels representative of the conditions airframes are subjected to when under flight conditions.
• Development of a novel test bench concept, which is easily adaptable to different geometries, and which allows the required boundary/load conditions to be introduced.
• Study of new metrological techniques to monitor panel deformation and capture damage during the test.
• Development and application of an advanced simulation methodology specific to the materials used in this project (Al-Li alloy and thermoplastic).
In this project Applus+ proposes to develop a test bench for curved fuselage panels that will guarantee:
• The adequate introduction of axial, bending, torsional and shear loads.
• The simulation of internal pressure changes that result from cabin pressurisation and depressurisation.
The Demonstrate project test bench will be suitable for testing a wide variety of large curved panels, of different lengths and curvatures with different load configurations and boundary conditions too.
Due to the variability of curvature radii and beam geometry of the panels, it will be necessary to design a test rig that allows the modularity of its components to be easily adapted to each configuration to ensure full structural certification.
The test rig proposed by the Demonstrate consortium requires only one curved panel segment instead of a complete cylindrical section of the fuselage, allowing new structural concepts and new materials to be validated at a lower cost.
The accuracy of the FEM models used to perform virtual tests can be evaluated by performing laboratory tests, then contrasting the information obtained with the results of the virtual tests.
To this end, this project will implement the Absolute Accurate methodology. This is an experimental approach developed by Applus+ that aims to provide a more robust way of identifying the boundary conditions of the tests performed by extending the instrumentation beyond the sample and monitoring the test bench.
Innovative tools developed by Applus+ will be used to improve the calibration and validation of FEM models.
These software solutions provide a digital infrastructure to facilitate the comparison of experimental test results and simulations, the creation of material charts used in the simulation software and the validation of the simulation model.
As the project aims to improve the quality of results, Digital Image Correlation (DIC) technology will be applied. This allows a faster and more accurate measurement of the deformation field of a structure.
The monitoring of the deformation field will be carried out in real-time thanks to the optimised algorithms of Digital Image Correlation (DIC).
New methods will also be applied to improve the detection of crack/delamination initiation and propagation. To perform the standard non-destructive inspection techniques used to monitor crack initiation, crack evolution (in metallic structures) and damage growth (in composites), the test needs to be stopped, and these inspections have a significant impact on test execution time.
To satisfy all these different requirements and bypass the delays that would be caused if using standard non-destructive inspection techniques, various damage monitoring techniques will be applied which do not require contact.
The test Plan has been started and is expected to be finished soon when all testing data will have been provided by the Topic Manager.
Innovative and flexible tooling to test curved panels has been designed by Applus+ and mostly finished. This design has been done based on advanced simulation performed by ATHENA and the results of a Mock-up developed by Applus+ and implemented at Applus+ laboratories to obtain experimental results of the proposed tooling geometry and solutions.
Advanced instrumentation (Digital Image Correlation and acoustic camera) methodologies have been investigated in preparation for the test execution.
Innovative and flexible tooling to test curved panels has been designed by Applus+ and mostly finished. This design has been done based on advanced simulation performed by ATHENA and the results of a Mock-up developed by Applus+ and implemented at Applus+ laboratories to obtain experimental results of the proposed tooling geometry and solutions.
Advanced instrumentation (Digital Image Correlation and acoustic camera) methodologies have been investigated in preparation for the test execution.
The ambition and foreseen advances beyond state‐of‐art of the various DEMONSTRATE technologies is summarised below:
* Test‐bench concept design and manufacturing: Adaptable, cost efficient and reliable sub‐component testing concept
* Flexible tooling for curved panel realistic load case introduction: Adaptable to large curved panel dimension and curvatures + Easier inner (pressurized) side panel + Tooling easy to setup and store.
* Innovative tooling design & Absolute Accuracy Methodology implementation: Sensing tooling provides accurate information about boundary conditions and FEM model update + Improve Virtual Test correlation with test.
* Virtual pre‐test simulations: Accuracy increase through modelling of the ‘as‐build’ panels + Accuracy increase through introduction of real fixture and loading system properties through Applus+ accurate methodology + Advancement of damage tolerance approaches,
* Virtual testing for load / BC definition: Use optimisation algorithms in the virtual testing process.
* Validation of simulations approaches: Introduction of a preliminary level 2 testing campaign to de‐ risk model developments, before complete validation at panel level.
* Applus+ IT Tools (PICSCI and E‐ Testing): Validate the tooling FEM Models by a specific Test Campaign + Reduce follow‐up costs by using E‐testing online monitoring system.
* Digital Image correlation accuracy: Uncertainty quantitative evaluation and optimization + Contact‐less real‐time inspection methodologies.
* Optical lock‐in IR thermography, Acoustic Camera, and Phase Array: Hot‐spot damage and crack/de‐bonding onset location for large structures + Contact‐less real‐time inspection methodologies and to detect growth reducing inspection time.
The main expected results and potential impact of the DEMONSTRATE project is summarised below:
* Light‐weighted primary aircraft structures: The DEMONSTRATE project by contributing towards the goal of experimentally validating novel advanced fuselage metallic (4th generation Al‐Li alloys) and composite (thermoplastic) integrally stiffened fuselage designs, is expected bring the targeted by the AIRFRAME ITD 5% CO2 reduction.
* Environmentally friendly manufacturing / assembly processes and recycling: DEMONSTRATE through its main technical achievements (Cost and time efficient, accurate and adaptable experimental test bench for curved panel demonstrators + Virtual Testing of Thermoplastic and Al‐Li Alloy integrally stiffened panels), will demonstrate the structural integrity of advanced fuselage concepts, manufactured through environmentally friendly manufacturing / assembly processes and recyclable materials, contributing to the reduction of emission of air pollutants, to the greening of air transport, as well as to the reduction of the environmental footprint of the aircraft production from a global life cycle point of view.
* Test‐bench concept design and manufacturing: Adaptable, cost efficient and reliable sub‐component testing concept
* Flexible tooling for curved panel realistic load case introduction: Adaptable to large curved panel dimension and curvatures + Easier inner (pressurized) side panel + Tooling easy to setup and store.
* Innovative tooling design & Absolute Accuracy Methodology implementation: Sensing tooling provides accurate information about boundary conditions and FEM model update + Improve Virtual Test correlation with test.
* Virtual pre‐test simulations: Accuracy increase through modelling of the ‘as‐build’ panels + Accuracy increase through introduction of real fixture and loading system properties through Applus+ accurate methodology + Advancement of damage tolerance approaches,
* Virtual testing for load / BC definition: Use optimisation algorithms in the virtual testing process.
* Validation of simulations approaches: Introduction of a preliminary level 2 testing campaign to de‐ risk model developments, before complete validation at panel level.
* Applus+ IT Tools (PICSCI and E‐ Testing): Validate the tooling FEM Models by a specific Test Campaign + Reduce follow‐up costs by using E‐testing online monitoring system.
* Digital Image correlation accuracy: Uncertainty quantitative evaluation and optimization + Contact‐less real‐time inspection methodologies.
* Optical lock‐in IR thermography, Acoustic Camera, and Phase Array: Hot‐spot damage and crack/de‐bonding onset location for large structures + Contact‐less real‐time inspection methodologies and to detect growth reducing inspection time.
The main expected results and potential impact of the DEMONSTRATE project is summarised below:
* Light‐weighted primary aircraft structures: The DEMONSTRATE project by contributing towards the goal of experimentally validating novel advanced fuselage metallic (4th generation Al‐Li alloys) and composite (thermoplastic) integrally stiffened fuselage designs, is expected bring the targeted by the AIRFRAME ITD 5% CO2 reduction.
* Environmentally friendly manufacturing / assembly processes and recycling: DEMONSTRATE through its main technical achievements (Cost and time efficient, accurate and adaptable experimental test bench for curved panel demonstrators + Virtual Testing of Thermoplastic and Al‐Li Alloy integrally stiffened panels), will demonstrate the structural integrity of advanced fuselage concepts, manufactured through environmentally friendly manufacturing / assembly processes and recyclable materials, contributing to the reduction of emission of air pollutants, to the greening of air transport, as well as to the reduction of the environmental footprint of the aircraft production from a global life cycle point of view.
Documentos relacionados
- Fig 2. Out-off the plan displacement measured with DIC showing a deformation for shear with inner pressure test similar to the expected from simulation.png
- Fig 1. Example of test on the mock-up at Applus Laboratories.png
- Fig 3. Indicative results of the final FE model of the metallic stiffened panel and the test rig.png