@article {21027, title = {Multi-frequency excitation of stiffened triangular plates for large amplitude oscillations}, journal = {Journal of Sound and Vibration}, volume = {333 }, year = {2014}, pages = {5817{\textendash}5835}, abstract = {Free and forced vibrations\ of triangular plate are investigated. Diverse types of\ stiffeners\ were attached onto the plate to suppress the undesirable large-amplitude\ oscillations. The governing\ equation of motion\ for a triangular plate, based on the von K{\'a}rm{\'a}n theory, is developed and the nonlinear ordinary\ differential equation\ of the system using Galerkin approach is obtained.\ Closed-form expressions\ for the free undamped and large-amplitude\ vibration\ of an orthotropic triangular elastic plate are presented using the two well-known analytical methods, namely, the energy balance method and the variational approach. The frequency responses in the closed-form are presented and their sensitivities with respect to the initial amplitudes are studied. An\ error analysis\ is performed and the vibration behavior, as well as the accuracy of the solution methods, is evaluated. Different types of the stiffened triangular plates are considered in order to cover a wide range of practical applications. Numerical simulations are carried out and the validity of the\ solution procedure\ is explored. It is demonstrated that the two methods of energy balance and variational approach have been quite straightforward and reliable techniques to solve those nonlinear differential equations. Subsequently, due to the importance of multiple resonant responses in engineering design, multi-frequency excitations are considered. It is assumed that three periodic forces are applied to the plate in three specific positions. The multiple time scaling method is utilized to obtain approximate solutions for the\ frequency resonance\ cases. Influences of different parameters, namely, the position of applied forces, geometry and the number of stiffeners on the frequency response of the triangular plates are examined.}, url = {https://www.sciencedirect.com/science/article/pii/S0022460X1400532X} }