Optimisation and failure criteria for composite materials by the boundary element method

The present paper deals with the analysis of the main failure, considering two quadratic criteria: the TsaiHill criterion and the Tsai-Wu criterion, for composite materials using the method of boundary elements. The developed formulation is applied to compute the stress and displacements of laminated composite structures plain submitted to loads in the structure plane, to show the influence of the direction of fibre in failure of the first lamina in a laminated composite materials, and the value of maximum tension that causes the failure, to find the optimum orientation of the directions of fibers into a symmetrical laminate, to minimize the failure criteria of Tsai-Hill and Tsai-Wu, and to optimum values for the fibers orientation angles that maximize the strength of the structure. The results are compared with other results from literature and show a good agreement.