Simulation analysis and experimental research of mechanical properties of T700 axial reinforced warp-knitted fabric composite

A new type of cohesive zone model(CZM) was used to study the composite interlaminar damage in this article. The model consisted of the bilinear damage criterion and damage evolvement could accurately predict the delamination propagation. The resin rich zones were recognized after impregnating referred to as knitting yarn induced fiber distortions (KYD) in the axial reinforced warp-knitted fabric. A new method to study the stress distributing around the KYD region when the unit cell was extruding and shearing was descripted based on the micromechanics theory of composite materials. The distortion is recognized to be dominant for the crack damage initiation. Bending and interlaminar shearing mechanical properties of T700 unidirectional warp-knitted fabric composite were tested. The discrepancy of the maximum strength between simulation and experiment about the bending and shearing is under 10%. The damage in laminates and interlaminar crack propagation damage were studied based on the finite element model.