Mechanical properties of polycarbonate under intermediate strain rates compression

Abstract

A high-speed hydraulic servo testing machine was used to carry out intermediate strain rate compression test of polycarbonate, and comparative experiments of low and high strain rate compression were carried out to verify the validity of the intermediate strain rate compression test. Based on the true stress-strain curves at various strain rates and temperatures, the mechanical properties of polycarbonate under compression at intermediate strain rates were obtained. The results show that polycarbonate undergoes four stages of elastic deformation, yielding, strain softening and strain hardening in intermediate strain rate. The strain rate and temperature dependence of material manifest as: yield strength and yield strain are increased with the enhancement of strain rate or reduction of temperature. On the contrary, when increasing temperature or reducing strain rate, the strain softening of the material are more apparent. Based on the experiments, a ZWT nonlinear viscoelastic constitutive model which can describe the compression process of polycarbonate in intermediate strain rates was constructed. This model can provide strong support for the structure design of transparent parts and the simulation of bird strike.

Keywords

• polycarbonate
• compression property
• strain rate
• constitutive model
• temperature