Comparisons of axial compression behaviors between four-directional and five-directional braided composite tubes under high strain rate loading

This paper reports the compressive behaviors of three-dimensional four-directional and three-dimensional five-directional circular braided composite tubes subjected to quasi-static and impact compressions along longitudinal direction. The compression tests of the three-dimensional four-directional and three-dimensional five-directional carbon fiber/epoxy circular braided composite tubes were tested under strain rates ranging from 0.001 to 884s(-1). The compression stress-strain curves were obtained and the damage morphologies were observed to analyze the damage behaviors. A microstructure model of the braided preform and the braided composite tube was established to calculate the compressive deformation and damage mechanisms with finite element method. The stress-strain curves, specific energy absorption, deformations, and damage morphologies were sensitive to the strain rate and the braiding structures. The three-dimensional five-directional braided composite tubes have higher compressive strength and specific energy absorptions than the three-dimensional four-directional braided composite tubes.