Temperature and strain rate sensitivity of modulus and yield strength of epoxy resin under compressive loads

As a common matrix in fiber-reinforced polymers, dynamic mechanical responses of epoxy resins are crucial for impact resistance design of reinforced polymer composites. In this study, we investigate the ambient temperature sensitivity on the mechanical performance of epoxy resin at various strain rates. Uniaxial compression tests are implemented with a universal machine and a split Hopkinson Pressure Bar (SHPB) both fitted with temperature chambers over various strain rates and ambient temperatures. The test results show that both the elastic modulus and compressive yield strength increase significantly as the strain rate goes up during each constant temperature, and the deformation process reveals the reduction of the plastic deformation localization of the epoxy material at higher ambient temperatures. Besides, the drastic changes are found in the improvement of compressive performance near the glass transition temperature under dynamic loadings. The variation of elastic modulus and yield strength influenced by temperatures and strain rates are analyzed and modeled, respectively.