SENSITIVITY ANALYSIS AND A MIXED APPROACH TO THE OPTIMIZATION OF SYMMETRIC LAYERED COMPOSITE PLATES

This paper studies the sensitivity analysis of the static structural compliance of symmetric layered composite plates with respect to the fiber orientation in terms of continuous and finite element discretized formulations. From the optimality criterion obtained based on the sensitivity analysis, it is found that the number of different angles of the fibers in an optimal plate is no more than 4 under rather general conditions. Making use of the sensitivity information and optimality criterion approach, we construct a mixed method for adjusting the fiber orientations to minimize the structural compliance of composite plates. Furthermore, the non-convcxity of compliances of composite plates is shown by numerical experiment.