Abstract
The finite element method is used to investigate the steady-state vibration with the geometrical nonlinearity. The nonlinear strain-displacement relations are employed and the in-plane displacement in middle plane is included in the model. The equations of motion are derived by applying the principle of virtual work. Reduced-order model is derived by transforming the equations of motion from the physical coordinates to the modal coordinates that defined by the non-classical mode. We can obtain only a few d.o.f. equations of motion in the modal coordinates, and the present numerical results are compared with the results obtained by applying a numerical integration directly to the equations of motion in the physical coordinates.
