Optimal design of symmetrically laminated plates for damping characteristics using lamination parameters

The present paper deals with the damping characteristics of symmetrically laminated plates. First, the effect of laminate configuration on the damping characteristics is investigated for cantilevered laminated plates. To examine the effect of laminate configuration, the concept of specific damping capacity is introduced and the damping characteristics are represented on the lamination parameter plane, where the damped stiffness invariants are newly proposed in this paper. Next, the optimal laminate configurations for the cantilevered laminated plates with maximal damping subjected to the constraints on the natural frequencies are determined by using differential evolution in which lamination parameters are used as intermediate design variables. The relation between the laminate configurations and the damping characteristics is discussed based on the concept of lamination parameters.