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 degrees C, while a cross shape heat concentration region is found along two crossed diagonal directions at 26 degrees 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 degrees C is similar to that at 26 degrees 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. (C) 2016 Elsevier Masson SAS. All rights reserved.