New mass optimization technique to achieve low mass BIW designs using optimal material layout methodology on the frontal vehicle crash

Abstract

BIW is the car body made of sheet metals welded together. Numerous researches were performed across the world to optimize and save mass on the car body design. This paper describes the new methodology which can be used to reduce mass of the BIW in a full frontal rigid wall impact crash model. The new methodology of identifying materials for the BIW components has been presented. Frontal crash load case has been considered for the research. Since Frontal impact is an evaluation to predict only the frontal performance, parts in the front impact load path like dash, A-pillar, reinforcements and hinge pillar region has been considered as the design space for the material layout optimization. List of materials have been provided as a variable for a list of parts in the BIW and DOE sampling were generated. Response for the DOE designs results have been extracted to study the sensitivity of the parts for the frontal load case and design performance was analysed. Subsequent multi-objective optimization have been performed based on the DOE results, to achieve an optimal material selection for each of the parts in the design space. Further performance improving techniques considering the sensitivity chart have been explored and optimal design with low mass and improved frontal crash performance have been achieved and presented. The use of this methodology on a full vehicle crash model has achieved 15.4 % mass saving with the performance better than the baseline design.