Thermo-mechanical numerical modeling on impact compressive damage of 3-D braided composite materials under room and low temperatures

This paper presents an approach to simulate the high strain-rate compression of 3-D braided basalt/epoxy composite materials under room and low temperatures. A microstructure model of 3-D braided composite was established to characterize a fully coupled thermo-mechanical response during the fast deformation. High stress state and low heat generation have been found in braided reinforcement. For out-of-plane compression, adiabatic heat concentration is along single diagonal direction at −100 °C, while a cross-shape heat concentration region is found along two crossed diagonal directions at 26 °C. There are fewer cracks among fiber tows at low temperature. Once the single diagonal shear failure occurs at low temperature, the 3-D braided reinforcement can not keep structure integrity and will be separated into two parts. For in-plane compression, the damage morphology at −100 °C is similar to that at 26 °C. Under the influence from the fiber tows, the adiabatic heating develops the zigzag-shape damage with veins and stripes along the braiding angle in composite, while the 3-D braided reinforcement still keeps its structural integrity.