抄録
Engineering plastics are used widely in the field of production of motor vehicles, electromotive tools and others. Most part of plastics has a remarkable strain rate dependency of the flow stress. It is, therefore, required to make clear the strain rate dependency of plastics over a wide range of strain rates on the order from 10^<-2> s^<-1> to 10^3 s^<-1>, and to make use of these properties for the simulation of the behavior of crashing parts of automobiles and of work-pieces under dynamic plastic working. In this paper, dynamic tensile properties of polyamide, polycarbonate, polypropylene, and ABS plastic were studied over the wide range of strain rate. The strain-rate dependencies of these tested plastics were made clear quantitatively. The strain rate sensitivity of the flow stress, for a group of plastics whose elastic modulus does not depend significantly on the strain rates, is expressed clearly by using the constitutive model as a special case of Tanimura-Mimura model 2009 (T-M 2009). The rate sensitivity of the flow stress, for another group of plastics whose elastic modulus depends obviously on the strain rates, is also expressed with high accuracy by using the T-M 2009.
