Optimum design of laminated composite plates containing a quasi-square cutout

In this paper, an attempt has been made to calculate the optimal values of effective parameters on the stress distribution around a quasi-square cutout using different optimization algorithms such as Particle Swarm Optimization (PSO), Genetic Algorithm (GA) and Ant Colony Optimization (ACO). To achieve this goal, the analytical results of symmetric laminated composite plates containing a square cutout have been used. The analytical solution can be achieved with the development of the Lekhnitskii solution method. This method is based on using complex variable method in the analysis of two-dimensional problems. In order to use the method in stress analysis of laminates containing a square cutout, by using conformal mapping, the area outside the square cutout is mapped to the area outside of a unit circle. Effective parameters on stress distribution around the square cutout in symmetric laminated plates considered as design variables include: load angle, cutout orientation, bluntness and the stacking sequence of the laminate. Cost function in this problem is the maximum stress created around the cutout calculated by the analytical solution method. Another goal of this paper is to investigate the performance of aforementioned optimization algorithms. The results show that the PSO algorithm converges earlier than the other two methods and have the better cost function.