A new approach for nonlinear vibration analysis of thin and moderately thick rectangular plates under inplane compressive load

In this study, a hybrid method is proposed to investigate the nonlinear vibrations of pre- and post-buckled rectangular plates for the first time. This is an answer to an existing need to develope a fast and precise numerical model which can handle the nonlinear vibrations of buckled plates under different boundary conditions and plate shapes. The method uses the differential quadrature element, arc-length, harmonic balance and direct iterative methods. The governing differential equations of plate vibration have been extracted considering shear deformations and the initial geometric imperfection. The solution is assumed to be the sum of the static and dynamic parts which upon inserting them into the governing equations, convert them into two sets of nonlinear differential equations for static and dynamic behaviors of the plate. First, the static solution is calculated using a combination of the differential quadrature element method and an arc-length strategy. Then, putting the first step solutions into the dynamic nonlinear differential equations, the nonlinear frequencies and modal shapes of the plate are extracted using the harmonic balance and direct iterative methods. Comparing the obtained solutions with those published in the literature confirms the accuracy and the precision of the proposed method. The results show that an increase in the nonlinear vibration amplitude increases the nonlinear frequencies.