Papers by Keyword: Lamination Parameter

Abstract: Since lamination parameters were found to represent the stiffness properties and the orientation of each ply, two major stages are defined to do the optimization. In the first stage which is called continuous optimization, the required lamination parameters will be obtained by VICONOPT but this has not been completed. This paper focuses on the second stage which is called discrete optimization. It consists of three programs and the major program is called OPBDP. Random values of required lamination parameters for 4, 8 and 16 plies lay-ups are chosen and assumed, then the results are computed and compared. What is more, a method called double up the plies is introduced and the results show that it could save a lot of solution time but is still only suitable for a small number of plies.

Abstract: Structural plate elements in composite structures are typically fabricated by stacking orthotropic layers, each of which is composed of reinforcing fibers and matrix materials. In this work, three optimum design approaches are compared to clarify the advantages and disadvantages for optimizing the buckling performance of laminated composite plates. The first approach is developed recently by the authors, where the buckling load is maximized with respect to the lamination parameters by a gradient method and then the optimum lay-up design is determined by minimizing the errors between the optimum parameters and parameters for all possible discrete lay-ups. The second approach is the layerwise optimization (LO) approach where the fiber orientation angle in each layer is optimized step-by-step by repeating one dimensional search. The third one is a direct application of a simple genetic algorithm (SGA). In numerical examples, three sets of results are compared to discuss on the methodology for buckling optimization.