Dynamic Constitutive Model for Polymers with Considering Strength-Differential Effect and Strain Rate Dependency

It is known that the dynamic behavior of polymers depends greatly on not only the strain rate but also the hydrostatic pressure, and furthermore, the volumetric change after plastic deformation is larger than that of the metal material. Therefore, it is necessary to clarify these material properties for high precision simulation of polymers. In this study, we newly extended the Tanimura-Mimura 2009 model to simulate the dynamic behavior of polymers which depends not only on the strain rates but also on the hydrostatic pressure, and implemented using the user subroutine function of the impact analysis code LS-DYNA®. Then, dynamic tension and compression tests were performed on polycarbonate specimens using the Sensing Block Type High Speed Material Testing System, and material parameters of the extended constitutive equation were determined. Furthermore, verification simulation by LS-DYNA using these constituent equation and material parameters was carried out. As a result, the simulation of the dynamic behavior of tension and compression agreed well with the dynamic test results, and the validity of the constitutive equation and its material parameters were confirmed.