An important challenging issue in the automotive industry is the light-weight, safe design and
enhancement of crash response of an auto-body structures. These objectives lead to increasing adoption
of high strength steel sheet for inner and outer auto-body members. This study evaluates the dynamic
tensile characteristics of high strength steel sheets, HS45R, TRIP60, DP60 and DP100, along the
rolling direction and transverse direction. Static tensile tests were carried out at the strain rate of
0.003/sec using the static tensile machine (Instron 5583). Dynamic tensile tests were carried out at the
range of strain rate from 0.1/sec to 200/sec using a high speed material testing machine developed.
The tensile tests acquire stress-strain relation and strain rate sensitivity of each material. The
experimental results show two important aspects for high strength steels: the flow stress is increased as
strain rate increases; the strain hardening is decreased as the tensile stress increases. The experiments
also produce interesting results that the elongation is not decreased even when the strain rate increases.