Dynamic responses and damage evolutions of four-step three-dimensional braided composites subjected to high strain rate punch shear loading

摘要

The objective of this study was to investigate the quasi-static and dynamic behaviors of three-dimensional carbon/epoxy braided composites under high strain rate punch shear loading. The punch shear tests were conducted at four strain rates, i.e. quasi-static, high strain rates ranging from 1320s(-1) to 3109s(-1), respectively. The meso-structure model of the three-dimensional braided composite was established based on the braided preform structure. The progressive damage and three-dimensional stress distribution in shear zone of the braided composite were numerically revealed with finite element method. The influences of braiding angles and strain rate sensitivity on the punch shear behaviors have been analyzed. There was good agreement between experimental and finite element method results. The finite element method results showed that the stress concentrated on the shear region. The braiding angle plays a significant role in the shear behaviors of the three-dimensional braided composites. It was also observed that the compression damage occurred on the front surface while tension damage occurred on the back surface. The fracture of three-dimensional braided composites under high strain rate shear loading increased with the strain rate increase.