Study on intra/inter-ply shear deformation of three dimensional woven preforms for composite materials

This study presents the in-plane shear and interlaminar shear behavior of the three dimensional (3D) angle interlock preforms with different fabric densities. Picture frame shear tests for the 3D woven preform were carried out, the non-linear curves of shear stress versus shear angle and the deformation mechanism were analyzed. A new test method was designed to characterize the inter-ply shear property. The samples after interlaminar shear tests were also investigated through the yarn pulling-out and meso-structure to discover their deformation and failure mechanism. The results have shown that the fabric density has significant influence on the in-plane shear and inter-ply shear properties of 3D angle interlock preforms and the shear performance decreases with the increasing of the fabric density. The lower fabric density, the better deformability. The inter-ply shear damage mode is the binder yarn pulling out from the fabric. It is expected that the study can provide an experimental basis for building up the theoretical model.