This paper is concerned with the optimum design of the B-pillar assembly induced by the high-speed side
impact of the vehicle. In order to simulate the deformation behavior of the B-pillar assembly, the simplified finite
element model of a B-pillar and a moving deformable barrier are developed based on results of the crash analysis of the
full vehicle model. In order to optimize the deformation shape of B-pillar, S-shaped deformation is targeted for
guaranteeing the reduction of injury level of the passenger dummy in the crash test. Tailor welded blank is adopted in the
simplified B-pillar model to control the deformation shape of B-pillar assembly. The thickness distribution of each part
which constitutes the simplified mode is initially selected as a design parameter. Important design parameters which
have effects on the deformation mechanism are selected with sensitivity analysis based on the design of experiment
technique. The objective function is constructed so as to minimize the weight and lead to the S-mode deformation shape.
The results in this paper fully show that the design criterion of B-pillar model can be simply applied to the part design at
the trial design stage for confronting the side impact test such as US-SINCAP and EURO-NCAP.