Buckling of long orthotropic plates including higher-order transverse shear

The problem of buckling of long orthotropic plates under combined in-plane loading is considered. An approximate analytical solution is presented. The concept of a mixed Rayleigh-Ritz method is used considering higher-order s hear deformations. The achieved load function of the half-buckling waveleng th and the inclination of the nodal lines are minimized via a simplex searc h method. For low transverse shear stiffnesses the model predicts buckling coefficients under in-plane shear load that are of the same order of magnit ude as those resulting from a uniaxial compressive load. For a thin plate, the critical sheer load is larger by 42% compared to the uniaxial case. The model also suggests that for highly anisotropic materials, such as paper, the critical load solution is still influenced by the shear deformation eff ect at width-to-thickness ratios above 100.