Experimental and numerical research on pseudo-ductility of carbon/glass hybrid composites with unidirectionally arrayed chopped strands

Abstract

Abstract The mutual exclusion of strength and toughness in carbon fiber reinforced polymer (CFRP) composites has long perplexed composite material designers, despite the benefits of high specific strength and modulus in CFRP. In this study, unidirectionally arrayed chopped strands (UACS) are introduced into thin ply carbon fiber prepregs, which are stacked with S-glass fiber prepregs to fabricate carbon/glass hybrid laminates (C/G). Tensile characteristics and the mechanism of pseudo-ductility are explored experimentally and numerically in C/G hybrid laminates with varying material component ratios. In C/G hybrid specimens with the slit length of 20 mm and the material component ratio of 6%, obvious pseudo-ductility is found, and the pseudo-ductility strain increases by 116% as the C/G ratio increases from 6–18%, while the plateau stress reduces by 35.1%. The delamination propagation is reasonably even and slow in specimens with length slits of 20 mm, therefore, there is no rapid load drop during the tensile process. When the slit length is shorter than 20 mm, the stress concentration at the slit tip rises dramatically, resulting in more unstable load drops in load-displacement curves. The stress-strain curves derived by simulation correlate well with the experiment data, indicating that the numerical model used in this study is accurate.