Abstract:

The impact crashworthiness between front-bumper and pillars (such as telegraph poles or trees)
was investigated. Some drop hammer impact tests were done for a car with its front-bumper being built from
ultra-high-strength hot-stamping boron-steel to reduce the bumper mass. The impact crashworthiness were
simulated and analyzed for the bumper with different thickness by a special finite element model with the
deformations, the stresses, and the energy absorption conditions of a front-bumper being taken as evaluation
indexes. The results show that the front-bumper using ultra-high-strength hot-stamping boron-steel reduces 40
mm within the biggest deformation, increases 7 kN within the biggest stress, and increases 0.1 kJ within the
energy absorptions compared with the original bumper from cold-stamping steel. Therefore, the hot-stamping
front-bumper has more excellent pole impact crashworthiness.

Key words: automotive safety, pole impact, crashworthiness, hot stamping, front bumper