An approach is presented to investigate the nonlinear vibration of stiffened plates.A stiffened plate is divided into one plate and some stiffeners,with the plate considered to be geometrically nonlinear,and the stiffeners taken as Euler beams.Lagrange equation and modal superposition method are used to derive the dynamic equilibrium equations of the stiffened plate according to energy of the system.Besides,the effect caused by boundary movement is transformed into equivalent excitations.The first approximation solution of the non-resonance is obtained by means of the method of multiple scales.The primary parametric resonance and primary resonance of the stiffened plate are studied by using the same method.The accuracy of the method is validated by comparing the results with those of finite element analysis via ANSYS.Numerical examples for different stiffened plates are presented to discuss the steady response of the non-resonance and the amplitude-frequency relationship of the primary parametric resonance and primary resonance.In addition,the analysis on how the damping coefficients and the transverse excitations influence amplitude-frequency curves is also carried out.Some nonlinear vibration characteristics of stiffened plates are obtained,which are useful for engineering design.
