Dynamic Response of Epon 828/T-403 Under Multiaxial Loading at Various Temperatures

The mechanical response and failure behavior of Epon 828/T-403 epoxy were experimentally obtained over a strain rate range of 1.7 × 10⁻⁵ to 4.7 × 10³ s⁻¹ and a temperature range of −190 to 100°C. Compressive loads were applied in both uniaxial and multiaxial manners. A modified split Hopkinson pressure bar was employed to perform dynamic experiments, whereas an Materials Test System (MTS810) was used to conduct experiments under quasi-static loading conditions to establish the trends in strain-rate sensitivity. Multiaxial compression was achieved by installing snug-fit steel sleeves on the lateral surfaces of the cylindrical polymer specimens. The effects of temperature were studied by heating/cooling specimens to desired temperatures before mechanical loads were applied. The experimental results show that the yield strength of the polymer increases with increasing strain rate until adiabatic heating offsets the strain rate hardening. Lateral confinement significantly increases the axial yield strength. Increasing temperature reduces both yield strength and Young’s modulus.