Oct 21, 2011

Cutting-edge LMS NVH work helps FutureSteelVehicle reduce body structure weight by 35%

Design optimization supports advanced steel technology to reach EV weight target.

By contributing cutting-edge NVH know-how and design optimization, LMS successfully helped reduce the weight of the FutureSteelVehicle (FSV) concept car body structure without compromising NVH performance. As part of the team working on the FutureSteelVehicle project, commissioned by WorldAutoSteel, LMS focused on early stage NVH simulation taking into consideration the advanced steel materials and advanced steel technology used in both EV and HEV vehicle body design. As part of the FSV project, the LMS Engineering Services team was challenged to optimize the NVH performance in parallel to the design team, ensuring that the target of 190kg (or less) body in white (BIW) mass and functional performance for an EV was maintained.

“Achieving low body mass and good NVH performance simultaneously is perceived to be a contradictory objective. For crash, reconciliation comes from the extensive use of high strength steels. In NVH, using thinner materials usually has a negative impact on NVH behavior. For us, the challenge was to propose clever body design changes, which struck a balance between low mass and acceptable NVH performance,” stated Dirk De Vis, Vice-President, Automotive at LMS International.

To achieve this, the team derived NVH targets from benchmarking an existing ICE/EV car and cascaded objectives to specific body targets. Detailed attention was paid to differentiating ICE and EV acoustic signatures to set the correct FSV targets.

Using LMS Virtual.Lab, LMS engineers simulated design changes in a balanced iterative loop with the WorldAutoSteel design team. Working together this closely during the early stages meant that significant design optimization could be undertaken to guarantee NVH performance while at the same time managing the vehicle weight. Particular attention was paid on one hand to the low frequency structural performance, while on the other hand also optimizing the mid and high frequency with the acoustic sound package.

The end result was a final body concept that was 35% lighter than the benchmarked platform. Having exceeded the target, the project demonstrated that innovative steel technology, like vibration damping steel, is an excellent material choice for meeting the stringent body mass reduction targets of green vehicles without compromising the NVH context. It also proved that early consideration of NVH in parallel to the concept design brings significant benefits.

“Achievement of such aggressive weight reduction, accomplished with advanced steels and design optimization, will set a new standard for vehicle design approaches in the future,” concluded Cees ten Broek, Director, WorldAutoSteel. “Early adoption of NVH in the design process, provided through LMS’ strong expertise, contributed significantly to FSV’s mass reduction success and to its contribution as a viable solution for greener vehicles.”