Material characterization of flexibly supported shear deformable laminated composite plates

This paper presents a method for nondestructively evaluating the system parameters of elastically restrained shear deformable laminated composite plates using measured natural frequencies. The proposed method is established on the basis of a multi-start global minimization method in which an objective function measuring the differences between the predicted and measured natural frequencies is constructed and a design variables normalization technique for expediting the convergence of the search of the solution is adopted. Vibration testing of several laminated composite plates with different boundary conditions was performed. Seven natural frequencies extracted from the vibration data of each of the plates were used in the proposed method to identify the system parameters of the plate. Excellent results have been obtained for the plates.