In the past, the static load−displacement curve was sufficient to predict the deformation of plastics. As plastics have increasingly been used in more applications such as automotive pasts, the dynamic material properties considering the strain rate and temperature become important. In plastics, the stress is typically very sensitive to the strain rate, but results for dynamic material properties at the intermediate strain rate ranged from 1 /sec to 500 /sec do not have been published sufficiently. This paper introduces a newly developed high speed material testing apparatus for tensile tests at the strain rate up to 500 /sec and dynamic material properties of plastics from experiments. Stress−strain curves were acquired for the polycarbonate and the polypropylene from the dynamic tensile test and utilized to obtain the relationship of the stress and the fracture elongation to the strain rate.
High speed material testing machine; Intermediate strain rate; Strain sate hardening; Plastics; Load ringing phenomenon; Dynamic material property