Crashworthiness Design of Automotive Body in White using Topology Optimization

Based on equivalent static loads method (ESL), a nonlinear dynamic topology optimization is carried out to optimize an automotive body in white (BIW) subjected to representative legislative crash loads, including frontal impact, side barrier impact, roof crush and rear impact. To meet the crashworthiness performances, two evaluation indexes are defined to convert the practical engineering problems into mathematic optimization problems. The strain energy is treated as the stiffness evaluation index of the BIW and the relative displacement is employed as the compliance index of the components and parts. The optimization problem could be changed into maximizing structural stiffness of the design space while constraining the relative displacements of the passenger cabin lower than a certain value to guarantee the stiffness of passenger cabin, constraining the relative displacements of the front and rear cabin greater than a certain value to increase the energy absorption during the crash process. The results provide a conceptual design which emphasizes the most efficient load paths and could be served as an effective guidance to the next-step BIW detailed design.