Dynamic Tensile Properties of CFRP Manufactured by PCM and WCM: Effect of Strain Rate and Configurations

Carbon fiber-reinforced plastic (CFRP) is a promising material to achieve lightweight automotive components. The effects of the strain rate and configurations of CFRP on dynamic tensile properties have not yet been fully explored; thus, its lightweight benefits cannot be maximized. In this paper, the dynamic tensile properties of CFRPs, tested using two different processes with two different resins and four different configurations, were studied with a strain rate from 0.001 to 500 s−1. The tensile strength, modulus, failure strain, and fracture mechanism were analyzed. It was found that the dynamic performance enhances the strength and modulus, whereas it decreases the failure strain. The two processes demonstrated the same level of tensile strength but via different fracture mechanisms. Fiber orientation also significantly affects the fracture mode of CFRP. Resins and configurations both have an influence on strain rate sensitivity. An analytic model was proposed to examine the strain rate sensitivity of CFRPs with different processes and configurations. The proposed model agreed well with the experimental data, and it can be used in simulations to maximize the lightweight properties of CFRP.

Experimental Investigations of 3D Woven Layer to-Layer Carbon/Epoxy Composites at Different Strain Rates

This paper reports experimental investigations of 3D woven carbon/epoxy composites on quasi-static and dynamic tensile properties in the longitudinal (warp) and transverse (weft) directions. Firstly, quasi-static tests were conducted to determine a baseline tensile strength and to find out the adequate specimen geometry required for dynamic testing. Secondly, dynamic tensile properties at intermediate strain rates (nominal strain rates from 0.1 to 200 s-1) were investigated alongside the corresponding failure mechanisms. Detailed information on failure patterns is obtained with strain field measurements from Digital Image Correlation (DIC) and CT scans. The results show that 3D woven composites are strain rate insensitive and the crack initiation is located near weft yarns and binding interlacement points due to the presence of resin rich areas.