Uncertain natural characteristics analysis of laminated composite plates considering geometric nonlinearity

In order to achieve the fine and high reliability design of laminated composite plates, the randomness of geometric and material parameters, along with the nonlinear mechanical characteristics is taken into deliberately account. A novel method for solving the uncertain natural characteristics is proposed, in which the uncertain natural frequencies first cover effects of the geometric nonlinearity and are obtained with a multiscale feature extraction and fusion network (MFEFN). Theoretical analytical solutions of the nonlinear natural frequencies and nonlinear frequency ratios are derived and then the statistical properties of the two uncertain natural characteristics are obtained. Influences of the random geometric parameters and material parameters on the two natural characteristics are further studied based on the sensitivity analysis. The accuracy of the present uncertain natural characteristics analyses is demonstrated by comparing linear natural frequencies, nonlinear natural frequencies and their statistical properties numerical results with those provided using other models available in the open literatures. The solving efficiency advantages of the proposed MFEFN-based procedure are clearly shown by comparing with MCS. The present research results provide theoretical basis and technical means for accurate analysis and optimal design of the laminated structures.