Reliability based design optimization for crashworthiness of a spot welded hat type member

Abstract

Crashworthiness design of auto-body members is an important issue to automakers. Both light and strong structures of an automotive body can be achieved by increasing crashworthiness of energy absorbing members categorized as spot welded hat type members. There were many experimental and theoretical researches on crashworthiness performance of hat type members. However, in most of the previous studies, influence of spot weld failure during the collision was ignored even though it is unavoidable and greatly affect crashworthiness of the member. Objective of this research is an optimization of a spot welded hat type member for crashworthiness enhancement considering spot weld failure during the collision. Reliability based design optimization with response surface method was employed to design a hat type member considering the effect of uncertainties on crashworthiness of the member. An optimization algorithm based on the sequential optimization and reliability assessment (SORA) was developed and employed to solve optimization problems for a spot welded hat type member. The results show that the suggested optimization algorithm can give reliable solution.