Characterization and analysis of in-plane shear behavior for glass warp knitted non-crimp fabrics based on bias extension experiment

Abstract

In this article, the in-plane shear rigidity modulus of five commercially available fabrics of glass warp knitted non-crimp fabrics (WKNCFs) was experimentally investigated by uniaxial bias extension test (UBE). The aim was to characterize and compare the shear behavior of relatively high areal density fabrics, while these fabrics could have good potential to be widely used in the composites field. In this work, five fabrics were included: a uni-directional, 2 bi-axial, and 2 tri-axial fabrics. To characterize the shear properties, stress equations were established to deliver the in-plane modulus of shear rigidity as a function to shear angle. The fabric structure of uni-axial or multi-axial had a different influence on the shear resistance mechanics along with the influence of the stitching pattern; both were also presented in the comparison of deformation mechanisms. It was found that the shear behavior of all five fabrics was dissimilar to each other.