APPLICATION OF GENETIC ALGORITHMS TO STIFFNESS OPTIMIZATION OF LAMINATED COMPOSITE PLATES WITH STRESS-CONCENTRATED OPEN HOLES

Recently, laminated composite plates have been applied to many aircraf t structures because their mechanical properties are superior to those of conventional materials. Since the laminates have anisotropic elast ic properties, an optimum design is needed to make advantageous use of composite laminates. The authors have proposed a successful object-or iented expert system to design laminated composites with actual constr aints. A solution to optimize the fiber orientation of stiffeners arou nd open holes, however, has not pet been developed because it is very difficult and requires stress redistribution analysis. In this study, therefore, genetic algorithms (GA) were applied to solve the optimizat ion problem by the object-oriented finite-element stress analysis meth od. Results obtained were as follows, (1) The GA method is applicable to an open hole model. (3) The random search method is easily applicab le to any model.