Based on the meso鄄structure of multi鄄ply multi鄄axial three鄄dimensional(3D) composite materials, the
different directional fiber bundles were regarded as the unidirectional composite materials. The stiffness matrix of uni鄄
directional composite materials was calculated by using the volume average method,and then the stiffness matrix of
multi鄄ply multi鄄axial 3D composite materials was obtained by the classical laminate theory. On the basis of total stiff鄄
ness matrix, the deformation of multi鄄ply multi鄄axial 3D composite materials and laminated composite materials were
simulated by software of ANSYS. By comparing the simulation results, it can be obtained that the multi鄄ply multi鄄axial
3D composites has the better in鄄plane property than laminated composites, and the maximum stress value of multi鄄ply
multi鄄axial 3D composites is about half of the laminated composites.