Study On The Dynamic Tensile Properties Of Polycarbonate Bars

Polycarbonate is a kind of typical thermoplastic polymer, which has extrusive clarity and good mechanical strength. As a kind of structure material, polycarbonate has been widely used in engineering applications such as vehicle and aircraft components due to its excellent mechanical properties. The purpose of the present research is to investigate and characterize the strain rate effect on the tensile behavior of polycarbonate bars.By means of numerous trial tests and finite-element dynamic analysis, the geometry of the specimen used in the dynamic tension testing was determined. Using MTS809 testing machine and bar-bar tensile impact apparatus, uniaxial tensile tests and loading-unloading tests on polycarbonate bars were performed under a wide range of strain rates from 10-3s-1 up to 1750s-1. The tension stress - strain curves at the rates of 0.001, 0.05, 380, 800 and 1750s-1 were obtained. Experimental results show that polycarbonate is a strain-rate sensitive material. The values of yield stress and unstable strain increase with increasing strain rate.Based on the experimental results, the modified Eyring model and a power law model by Richeton were used to describe the strain rate effect on the yield behavior of polycarbonate. The model results indicate that this model can give a better description of the relation between the yield behavior and the strain rate for the polycarbonate. The ZWT model was adopted to describe the constitutive responses of polycarbonate under quasi-static and dynamic loading conditions. The correlation between the experimental data and the model is good, which indicates that the ZWT model can capture the nonlinear elastic response characteristics of the polycarbonate within the rate range investigated in the present paper.