Optimization of laminated composite structures under nonlinear dynamic loading using the equivalent static load method

As the application of composite materials increases, analysis and optimum design for various dynamic loads as well as static loads are required. In this paper, we present an optimal design study using the equivalent static load method for laminated composite structures subjected to various nonlinear dynamic loads. First, the dynamic analysis of the laminate composite structure was performed using the finite element method. Next, the equivalent static load at each time step was calculated using the calculated dynamic response, and the static response optimization of the composite structure was performed by applying the calculated equivalent static load as a multi-load condition. Then, optimal design was performed by minimizing mass or maximizing strength by designing stacking thickness and stacking angle as design variables by applying various dynamic loads for the three different composite material structures. As a result of the optimization, the results of the conventional dynamic response optimization method, the error of less than 0.1 %, and the convergence speed up to 18 times were shown, and it was verified that the convergence speed was excellent while ensuring the accuracy of the solution.