Buckling analysis of tri-axial woven fabric composite structures. Part II: parametric study––uni-directional loading

The buckling behavior of simple tri-axially woven composite structure is studied. There are two cases of these simple structures that are considered: one is a basic structure and the other is the modified basic structure where additional weavings are added to make the structure longer and wider. The basic composite structure consists of six individual curved tows and they are bonded by resin at interlaced parts of the tows. The structure is subjected to uni-directional loading. The sensitivity of the buckling behavior of the basic tri-axial structure to the change in the boundary conditions and to the imperfection due to initial configuration is investigated. The sensitivity analysis of buckling behavior to the in-plane aspect ratio of the structure is also studied. The numerical results and corresponding physical explanations are given. In order to gain some insight into the buckling behavior of more complicated tri-axial woven fabric composite structures, the buckling analysis of the modified and enlarged basic tri-axial composite structures subjected to uni-directional loading is conducted. Numerical results reveal that these modified and enlarged basic tri-axial composite structures have almost the same buckling behavior as the basic tri-axial structure. In order to provide confirmation to the numerical solutions and to provide simpler ways to obtain the results, approximate analytical solution corresponding to the basic tri-axial structure has been derived by using equivalent multi-layered plate theory. The numerical result obtained for the basic tri-axial structure is compared with the analytical solution. The investigation of the effect of the resin on the basic tri-axial woven composite structure shows that the Young’s modulus of the resin has little effect on the buckling behavior of the basic tri-axial structure due to the interaction of the woven tows constituting the structure.