Multi-scale modelling of Thin woven composites

Abstract

It has been observed that the bending stiffness of thin composites made with two ply plain-weave carbon fibre reinforced plastic are not accurately modelled by classical laminate theory. More accurate predictions can be obtained through a homogenization technique by idealizing it to a thin Kirchhoff plate. The geometric properties of the model are obtained through the micrographs and the tow properties are calculated from the appropriate rule of mixtures. This paper presents a micromechanical analysis to predict mechanical properties of symmetric twoply plain-weave laminates of carbon fibre composites modelled with Abaqus/Standard commercial finite element software. A homogenized representative unit cell is simulated with periodic boundary’ conditions which enforce the mid-plane strains and out-of-plane curvatures of the homogenized Kirchhoff plate model. The standard 6*6 ABD stiffness matrix is obtained by applying virtual work to six models, each representing unit strain or curvature in the specified direction. The sensitivity to idealized tow cross-sectional dimensions and weave profile is examined by varying respective parameters. Finally the analytical results are compared with the experimental results available in the literature for validation.