Abstract:

In order to reduce the mass of car body B pillar, improve its side crashworthiness and simplify the manufacturing process, a method using the hot formed B pillar was proposed. The method produces the B pilllar reinforcement panel with uniform thickness and varying yield strength by different cooling rate at hot forming. To make the distribution of the yield strength in the hot formed B pillar reasonable, an optimization design was performed by the finite element analysis. Taking a certain car as an example, an optimal distribution of the yield strength in the B pillar reinforcement panel material was obtained using the numerical optimization method of response surface and component collision simulation analysis. The optimized result was simulated with the vehicle side collision and compared with the original vehicle. The obtained results indicate that the car body using the optimized hot formed B pillar reinforcement panel with varying yield strength can reduce mass by 0.773 kg and improve the vehicle side crashworthiness.

Key words: vehicle engineering, gradient of yield strength, hot forming, design optimization, B-pillar reinforcement panel, side collision