FSV & FGPC Mass Reduction
ETA Achieves Significant Mass Reduction for Passenger Compartment & Future Steel Vehicle with New Method
Engineering Technology Associates, Inc (ETA) achieved significant mass reduction for the Auto/Steel Partnership (A/SP) (www.a-sp.org) Future Generation Passenger Compartment (FGPC) Phase 1, FGPC Validation Phase, as well as for the WorldAutoSteel (www.worldautosteel.org) Future Steel Vehicle (FSV) Pilot Project. The mass savings was realized by applying ETA’s newly developed, proprietary Accelerated Concept to Product (ACP) Process. The engineering method is an innovative, holistic product development process with multi-disciplinary (MD) loading based on topology and 3G (geometry, grade, and gage) optimization.
ETA’s advanced product development process, ACP, significantly reduces product mass and cost, while remarkably improving design function, quality, and performance. The new method is proving to be the future of structural product design and has potential to influence and better products in a variety of industries.
ETA was contracted for FGPC Phase 1 by the Auto/Steel Partnership, to assist in a design study based on the ULSAB-AVC (Advanced Vehicle Concepts) (www.ulsab-avc.org). The goal was to develop a lightweight passenger compartment using Advanced High Strength Steel (AHSS). The vehicle packaging was adapted for both a conventional diesel and hydrogen fuel cell powertrains.
The ACP Process could be employed on the diesel variant resulting in a total mass reduction of 30% compared with the passenger compartment of the same class. This was achieved while maintaining the required all new and future (2015) crash/safety performance, stiffness and durability. A series of sensitivity studies proved the robustness of the design through its ability to accommodate variations in the vehicle’s curb weight and side impact barrier height.
During the Validation Phase (Phase 2) of the project the improved methodology was applied to a U.S. OEM’s present production (2008) donor vehicle. Again, holistic topology and MD-3G optimization techniques were applied to the vehicle’s passenger compartment using AHSS. This phase of the project served to validate the guiding principle developed in the previous phase. This principle theorized that the key enabling feature of robust design optimization is the development of primary loadpaths within the structure. The team demonstrated how the loadpath concepts developed in Phase 1 could be successfully applied to any production vehicle.
The project achieved an overall mass reduction for the passenger compartment by 15%. The program also proved that advanced joining technology (laser-weld or adhesive bonding) could increase the overall mass reduction to 20%. Again, sensitivity studies established the viability of the loadpaths and robustness of the optimized design.
Similarly, ETA was contracted to demonstrate its improved ACP Process for the WorldAutoSteel Future Steel Vehicle (FSV) Pilot Project, which was just recently completed. The objectives were to validate the proposed, new and improved, ACP Process that is intended for use in the full vehicle program by applying the methodology to the A/SP LWFE (light-weight front end) front rail and attain mass savings beyond those achieved in the LWFES project. For the Pilot Project, the team took a “clean sheet” approach, meaning that the design was not based on existing geometry.
The first step within the “clean sheet” approach was to define the available design space for the rail. The defined space is purely packaging volume without any structural considerations. Topology optimization was then used to identify the primary design envelope within the design space. The primary design envelope defined the basic shape of the front rail that best suited the requirements of the MD-3G optimization load cases, crashworthiness, stiffness, and durability loads. The longitudinal rail was then designed using detailed MD-3G optimization and the robust final product design was defined in a CAD model.
The results of the fully optimized rail design achieved a 27% mass reduction over the A/SP LWB concept (a laser welded blank concept used for comparison purposes) and 45% mass reduction over the original donor vehicle’s design. Ultimately, the project successfully established the effectiveness of the proposed holistic design process for use in the full Future Steel Vehicle program. ETA is currently applying the ACP Process to a full vehicle structure, while the method is expanded to address manufacturing efficiency including cost of labor, material, and tooling.
There are many advantages to using ETA’s ACP Process, including the ability to disregard underlying assumptions that can inhibit the design. Additionally, the optimum load path, geometry, material, and gage are unconstrained by historical engineering judgment. Most importantly, it also allows for non-intuitive solutions for structural performance and can generate non-intuitive optimized shapes and component configuration.
Comprehensive goals are achievable using the ACP Process as CAE/CAD designs are synchronized and change simultaneously, maximum mass reduction is possible, design robustness and efficiency can be significantly improved, the number of components in a system or sub-system can be reduced and manufacturing efficiency can be achieved (labor, material, tooling). Additionally, highly optimized and advanced solutions can be applied in both a linear and non-linear environment. The ACP Process has unlimited potential and will be applied in a variety of industries for structural product development.
More information regarding ACP
For more information, please email This e-mail address is being protected from spambots. You need JavaScript enabled to view it , or call (248) 729-3010.
