Dynamic Compressive Behaviors of Multi Directional Woven Composite Laminates at Different Strain Rates

Abstract

This paper discusses the experimental study on the response of multi directional satin weave E-glass/epoxy composite laminates subjected to quasi-static and high strain rate compression loading along in-plane direction. Composite laminates were fabricated from satin weave glass fabric reinforced epoxy matrix pre-impregnated tapes which were manually laid up into laminates with stacking sequence of [45/-45/0/90] The low strain rate tests were conducted with an INSTRON™ testing machine, and the high strain rate tests done using a pulse shaper modified compression Split Hopkinson Pressure Bar (SHPB) apparatus. Compressive strength, modulus and strain at peak stress are evaluated experimentally at different strain rates. The results show that compressive strength, modulus and strain at peak stress are rate sensitive and enhanced at high strain rate compared with those at quasi-static loading. Under high strain rate loading, compressive strength and modulus increase as the strain rate increases. Optical and microscopic graphs on the specimens are carefully examined to determine operative failure modes. With the studied strain rate regimes, the failure modes are observed to change from splitting followed by fiber kink buckling to predominantly delamination and shear fracture as the strain rate increases from quasi-static to high strain rate.