Stacking sequence optimization of composite cylindrical panels by sequential permutation search and Rayleigh-Ritz method

A novel sequential permutation search (SPS) optimization algorithm is proposed for the stacking sequence design of composite cylindrical panels to maximize the fundamental frequency. The SPS exploits the sensitive information of bending stiffness, the convex property of lamination parameters, and the bending-twisting coupling feature of composite laminates. By assigning identical ply orientation at respective stacking positions and designing the sign configuration independently, a good initial point is identified. Subsequently, sensitive ply orientation is detected at the innermost position or a specific stacking position, and this sensitive ply orientation is adopted to replace other existing ply orientations from the inner to the outer position to seek the optimum. Such procedures are repeated till no sensitive ply orientation is available at any stacking position. In addition, the sign optimization algorithm (SOA) is coupled in the SPS to regulate the bending-twisting coupling effects. The Rayleigh-Ritz method is developed to assess the vibration frequencies which can accommodate arbitrary boundaries. The optimal results of the SPS are compared with those of layerwise optimization approach (LOA) and genetic algorithm (GA), demonstrating the robustness and efficiency of SPS.