Out-of-Plane Compressive Behavior for UHMWPE/ Polyurethane Composites after Hygrothermal Treatment

Quasi-static and high strain rate compressive behaviors and failure mechanisms of hygrothermal treated ultra-high molecular weight polyethylene/polyurethane (UHMWPE/PU) composites have been studied in this paper. Firstly, the UHMWPE composites were immersed in water at 70 ℃. The out-of-plane compression test was then performed on the dry/wet state specimens at quasi-static states (0.001-0.01 s^-1) and high strain rate states (800-2 400s^-1). The split Hopkinson pressure bar (SHPB) was adopted in the dynamic tests and waveform shapers were used to smooth and control the incident pulse. The results show that there are two platforms for the water absorption curve of UHMWPE composites. The absorption of moisture reduces the quasi-static compressive strength of the material while initially increasing, then decreasing the dynamic compressive strength. Matrix plasticization, fiber/matrix interface degradation and void expansion are the main factors affecting the irregular change of static/dynamic compressive strength of UHMWPE composites.