Nonlinear flutter of laminated plates with in-plane force and transverse shear effects

Based on a simplified higher-order shear deformation plate theory (SDPT) an d von Karman large deformation assumption, a high-precision higher-order tr iangular-plate element that can be used to deal with transverse shear effec ts is developed for the nonlinear flutter analysis of composite laminates. The element presents no shear-locking problem due to the assumption that th e total transverse displacement of the plate is expressed as the sum of the displacement due to bending acid that due to shear deformation. Quasi-stea dy aerodynamic theory is employed for the flutter analysis. Newmark numeric al time integration method is applied to solve the nonlinear governing equa tion in time domain. Results show that the in-plane force on the plate will increase the maximum plate displacement but will not influence the maximum plate motion speed. However, the aerodynamic pressure will increase both t he maximum displacement and velocity of the plate. The transverse shear wil l have profound influence on the flutter boundary for a thick plate and und er certain conditions it will change the plate motion from buckled but dyna mically stable to a limit-cycle oscillation.