Influence of AHSS Part Geometric Features on Crash Behavior

Advanced High Strength Steels (AHSS) are replacing conventional high strength low-alloyed steels (HSLA) in crash sensitive body in white (BIW) applications. Along with innovative product design, they offer superior crash energy management and vehicle weight reduction potential. However, Controlling springback and dimensional accuracy is one of the major concerns in manufacturing AHSS parts. One of the most effective springback control techniques is to design a part with added geometric features such as side stiffening beads, state beads, top hat beads, and embossments, etc. at the product design stage. On the other hand, product design communities tend to believe that the above listed features may result in premature crash initiation in the part. This paper uses an innovative and experimentally verified finite element method (FEM) for crash sensitive component design and optimization. It proves that optimized geometric surface features such as stiffening beads applied for AHSS part springback control can also offer superior crash performance and improved component crashworthiness. In addition, this paper provides evaluation and analysis results of several case studies together with practical geometric solutions applicable to BIW components such as rails, cross-members, beams, rockers, etc.