To transform vision into reality, ALMA’s ambition to lightweight EVs comes with a lot of heavy lifting.
Since 2021, ALMA consortium partners poured in hours of work and creative energies to facilitate and implement the cross-cutting collaboration between nine organisations from four European countries, each with specific green skills and different systems thinking approach. United under the ALMA banner, the consortium partners – CTAG ( overall project coordinator), Fraunhofer ITWM, ArcelorMittal, Ford of Europe, RESCOLL, Innerspec, BATZ, TNO and ISWA – joined forces to implement the EU Commission funded project (Horizon 2020 Research and Innovation programme). Ultimately, the objective is to create a lightweight battery electric vehicle (BEV) using less materials and energy, and thereby lowering the overall environmental impact, from design to end-of-life (EOL) phase.
As we are nearing the finish line, it is an opportune time to highlight and reflect on the project progress till now. Following the meetup in Brussels last year, the consortium met again in Petten, The Netherlands earlier this year to discuss the project development. Indeed, progress has been made on several fronts.
One of the main achievements is the concept car’s remarkable mass reduction of 160,5 kg, representing 22% weight savings compared to the baseline BEV.On the basis of the selected final bill of materials, the resulting total carbon footprint was also reduced from 43.5 to 27.8 kg CO2-eq, a reduction of 36%.
Ford conducted several iterative loops using CAD and CAE (CAD Assisted Engineering) tools, which allowed them to virtually validate the ALMA design against six distinct crash and NVH (Noise, Vibration, Harshness) scenarios. Following iterative improvements, the final Bill of Materials (BOM) was categorised into four groups: unmodified components, steel components with optimised thickness (AHSS, hot forming steels, hybrid grades), steel components with functional integration (AHSS, hybrid grades), and SMC components (dash panel, battery lid).
Currently, consortium coordinator CTAG is involved, together with end-users, in the final validation loop of the novel ALMA concept.
Materials (High strength steels + Composites)
Work Package 2 (WP2): Lightweight multi-material concepts
Objective: The project will deal with the finetuning of two existing material families suited for lightweight structural applications in road transport.
Project highlights: One of the main thrust areas of the project is to develop and optimise cutting-edge materials to achieve lightweighting of different vehicle parts, including the usage of Advanced High Strength Steel (AHSS) provided by ArcelorMittal and Sheet Moulded Composite (SMC) by BATZ.
For this purpose, ArcelorMittal has been actively collaborating with CTAG and Ford to implement the advanced materials, including Ductibor 1500, which is currently in advanced development. The primary goal has been to achieve substantial mass savings while maintaining comparable crash performance. To enhance efficiency in car production, ArcelorMittal proposed a Multi-Part Integration concept, streamlining the process by consolidating approximately 10 parts into a single, large component through a single stamping operation. Two validated concepts within this approach are the H-Frame and the Door Ring. Additionally, ArcelorMittal is actively supporting prototyping efforts, stamping H-Frame and Door Ring demonstrators, and providing materials for Ford’s Battery Pack prototype.
Read more on lightweighting from RTR conference
In addition, ArcelorMittal has also contributed to the finetuning of advanced steel materials, such as FortiformS1270 (AHHS), Duplex (steel with reduced density) and Ultimate (a sandwich of steel/plastic/steel laminate material).
Latest update: For the abovementioned three materials, ArcelorMittal has shared their progress report below:
- FortiformS1270 (AHHS): We have casted the product, stamped parts and validated the in-use properties of the material to validate the development.
- Duplex: Despite being a challenging steel grade with a unique chemical composition, we have conducted successful casting trials and identified counter measures to ensure robust industrial casting.
- Ultimate: We have developed the product, produced some trail sheets and stamped material to validate the material properties.
Project highlights: When the vehicle structure was unveiled, BATZ conducted a comprehensive analysis of its various components and systems to determine the most optimal approach for developing alternatives with a primary focus on lightweighting. Considerations like estimated cost played a crucial role in these proposals, necessitating the use of materials and technologies readily available for mainstream vehicles rather than exclusive or exotic car materials like Carbon Fibre, which, while exceptionally lightweight, come with a high price tag. Simultaneously, the imperative to achieve weight advantages led to the integration of multiple original metal sheet stamped parts into single components, thereby reducing the reliance on costly tools and joining processes.
The selected components for development included the Battery Lid, with specific crash protection requirements for safeguarding the battery, and the Cowl Panel, a pioneering global novelty in SMC material for this vehicle type, subject to significant stress and responsible for upholding structural integrity during frontal crashes.
Latest update: During the last year, BATZ’ main work was to develop the design of the Cowl Panel in SMC/SMC-Tex alternative materials while providing help to other partners to refine and evaluate its correct performance during the crash. Currently, the material rheologic flow inside the mould has been simulated as closely as possible with the currently available solvers, and the mould production has started to have physical demonstrators before end of 2023. These demonstrators will later be tested by CTAG.
Holistic Multi-function Eco-Design
Work Package 3 (WP3): Holistic multi-function eco-design and optimised CAE analysis of full vehicle structure
Objective: Design the most promising vehicle multi-material structure by presenting an affordable weight reduction with highest possible performance. Both the full vehicle structure and the subsystems/ components design will be performed in iterative loops through CAE analysis and entirely supported by the LCA & LCC performed in WP1.
Project highlights: Regarding the full vehicle CAE analysis, consortium partner Ford has conducted the optimisation of the CAE analysis of the vehicle structure (including all work packages where Ford is involved) based on the inputs from previous work packages (WP1, WP2 and WP3.1). In relation to this, workflow is divided into Phase I and II. In Phase I, full vehicle CAE analysis adaptation of the current ICEV model to BEV model was made, and total of nine iterations were performed to fulfil the base ICEV crash requirements. Eventually, iteration nine – after upgauging 18 parts and adding 52kg to the body in white – became the baseline (reference) BEV for ALMA project, following which the whole CAD was converted to CAE. Ultimately, in Phase II CAE analysis, the ALMA BEV achieved a weight reduction of more than 20% weight reduction.
Latest update: Overall, in the CAE workstream, Ford has performed final loops of CAE crash simulations to meet all safety requirements listed in the requirements report. For visualisation purposes, Ford will display some videos at the final GACS Expo 2023 event in Stuttgart, Germany, including the physical prototype and crash simulations.
Efficient Separation at End-of-Life (EOL)
Work package 4 (WP4): New Manufacturing and Reversible Assembly Methods
Objective: Develop new technologies and manufacturing methods to create efficient end-of-life solutions.
Project highlights: End-of-life solutions include efficient separation of materials, one essential requirement to transition from a linear to a circular system. Beyond lightweighting, our eco-design principles enable us to consider design, production, use-phase, and end-of-life solutions. This means refocusing attention to circularity topics beyond just reducing weight which may benefit the use phase but may complicate and increase the environmental cost in all others.
Introducing debonding on demand! ALMA consortium partner RESCOLL developed an innovative reversible assembly method using debondable adhesives and primers that will enable efficient separation of materials at the end-of-life that is both cost-effective and sustainable. In other words, a glue that separates on demand when applying heaat! Here, RESCOLL developed adhesives and primers with debonding on demand capability (heat triggered). In compliance with ALMA’s life cycle approach informing the BEV development, the INDAR technology allows easy disassembly of bonded parts for maintenance, upgrade, or recycling. To this end, adhesives that are supposed to debond at 130°C were developed.
For WP8 (Circular demo and complete systems validation), the aim is to make a simplified demonstrator of the battery tray structure. The demonstrator is an assembly of a squared steel frame from ArcelorMittal with a composite sheet from BATZ to simulate upper battery cover. Utilising a 6-axis robot, RESCOLL developed trajectories with tasks, such as flame treating the SMC sheet, depositing adhesive onto the composite, assembling the frame and cover. After the adhesive has fully polymerised, the assembly will undergo induction, followed by disassembly of the frame and cover.
So far, in July, a video of the 6-axis robotised program’s ability to perform the task was released. The principle of the assembly is about lifting the composite part, activating it (with flaming for the first video), depositing the glue, then bonding with the steel frame. Subsequently, RESCOLL optimised the programme with several adjustments. Then, flaming was replaced with plasma, trajectories of the robot were optimised, and improvements made to the way pressure is applied for the bonding step.
Latest update: Right now, plasma is being used to activate the surface, adjusting the deposition of the adhesive. Trials are also being conducted with the inductor to include the induction into the second program. The goal is to show bonding and debonding, performed with robotised programs.
Experimental and Model-based Characterisation
Work package 5 (WP5): Verification of the structural integrity, reliability, and long-life service of the auto body structure.
Objective: Experimental and model-based characterisation of material samples and coupons developed in previous WPs to verify the structural integrity, reliability and long-life service of the multi-material body structure at multiscale level.
Highlights: Fraunhofer ITWM’s contribution involved numerical modelling of SMC materials, with their stiffness and strength depending on the fibre reinforcement direction. Accurate simulation models in the design phase are crucial to avoid significant discrepancies between simulations and experiments, which would necessitate thicker components and large safety factors which results in higher material usage. Precise material performance prediction allows the designer to optimise and minimise material usage. In the process, Fraunhofer ITWM developed simulation methods, including a process simulation tool for accurate fibre orientation prediction in complex geometries and a calibrated material model considering anisotropy and complex failure behaviour, minimising the need for experimental calibration. Extensive component-scale tests validate the accuracy of the material model. Moreover, they conducted CT analyses of SMC material microstructures for validation. Finally, these material cards were applied to plastic components developed by BATZ as steel replacements.
The image below shows Fraunhofer’s innovative tool FeelMath, which is used to conduct virtual experiments on material cards at mesoscale.
Latest update: In close collaboration with Ford, BATZ and CTAG, Fraunhofer ITWM demonstrated that the plastic components, developed by BATZ, meet crash safety requirements, significantly reducing vehicle weight. The experimental effort for model calibration was kept to a minimum.
Work Package 6 (WP6): Efficient inspection to enable repair and reuse
Objective: An in-service inspection and monitoring system based on acoustic signature analysis will be developed and tested to extend the options at the end-of-life to include the possibility to repair and reuse the vehicle structure.
Project highlights: Transitioning from a linear to a circular economy system requires efficient monitoring of the health of materials used in a product to enable reuse, repair and recycle. In ALMA’s case, Innerspec is tasked with monitoring the integrity and reliability of the BEV structure. To implement the system, Innerspec has been engaged in the development of an 8-channel acoustic-based structural health monitoring system hardware. The last few months marked the final development phase for the acoustic monitoring solution. During this time, focus was on enhancing hardware and software for optimal performance across use cases, with a strong emphasis on debugging.
Latest update: Development stage is now complete, while work is on to finalise the assembly of the latest prototype model. After this, the implementation of the demonstrator will begin. All the tasks are completed, only validation remains.
Innerspec has received good signals in both use cases, namely composite parts and suspension springs. While the information was valuable in both cases, some applications are not reliable enough to provide advanced localised health status diagnostics.
Readiness for existing and new materials
The project has focused on two scenarios with different materials to demonstrate the versatility of the developed solution. For composites, Innerspec is confident of evaluating wear of the composite to ascertain if damages are occurring at critical points due to the loss of mass. They can also scan the full part to detect delaminations, cracks and porosity. For steel parts, surface and subsurface inspections can detect cracks and residual stress build up. Results are optimistic, although admittedly the final applicability of an embedded car structural health monitoring system remains to be explored, since the rate of degradation of parts is not a critical issue for cars and the associated cost is relatively high. Alternatively, off-line monitoring schemes could be implemented during maintenance to provide the same information while greatly reducing the cost.
Recycling and recovery
Work package 7 (WP7): Effective solutions for recycling and recovery
Objective: Aligned with the circular approach, possible solutions for recycling and recovery of the materials used will be assessed, identifying the most sustainable and economical routes for end-of-life recycling of materials.
Project highlights: During the past year and a half, TNO experimented with both the SMC and the steel laminate materials. During the project, a material switch was made from SMC 7150 to SMC-Tex (including glass fibre (GF) component), which have similar densities, but the latter was favoured for higher strength and greater absorption capacity. One of the crucial questions that needed answering was the quality of the glass fibre recovered to assess the re-useability in other applications. Accordingly, solvolysis tests in T7.2 (Recycling and recovery of composite materials) on the SMC material showed promising results. Pyrolysis tests already showed that 5 wt% of the SMC feed can be valorised via styrene recovery. Now, tests showed that recovery of the fibre and filler minerals was successful as well, retaining the shape and size of the fibres in the SMC-Tex. The analysis on the quality of the recovered materials from both solvolysis and pyrolysis show potential for re-use.
Latest update: The final deliverables for WP 7.2 (Recycling and recovery of composite materials) and WP 7.3 (recycling and recovery of steel-based materials) have been finalised, submitted and activities are finished. We are now having discussions on whether we can publish a paper on the pyrolysis and solvolysis part as we got nice results from the both recycling processes and would like to publish that in a journal, possibly after patenting some key aspects of the solvolysis work.
Meanwhile, ArcelorMittal carried out the recycling trials of Fortiform S1270, following which the full recyclability of the steel has been established. Furthermore, ArcelorMittal conducted recycling trials of the Ultimate (laminate) to validate that the recycling of this product will not produce any risk of pollution due to the combustion of the plastic. The sensitive point in this project was with the laminates which contain a layer of polyamide.
However, through shredding trials, ArcelorMittal has validated that no polyamide fragment was liberated, so there is no risk of increasing the waste part of shredded vehicles ending up in landfills.
Circular Use Demonstration in Real Deployment Conditions
Work package 8 (WP8): Circular Demonstration and Model-based Characterisation
Objective: Full virtual verification of the engineering approach and demonstration of the circular use in real deployment conditions will be performed evidencing that the project proposed strategy has reached an integrated and mature level.
Latest update: Currently, Ford has assembled the front-end of the BEV, and to ensure prototype stability, a dummy steel dash panel has been preliminary installed. When the dash panel prototype from BATZ will be finished, dummy part will be uninstalled and the SMC dash panel integrated into the prototype.
Our ambition is being realised, thanks to the European Union’s Horizon 2020 Research and Innovation programme grant.
Watch this space for more updates.