Dynamic and buckling analysis of composite laminated plates with and without strip delamination under hygrothermal effects using finite strip method

The effect of hygrothermal conditions such as temperature and moisture on free vibration frequency and buckling load of composite laminated plates was investigated in present article. For this purpose, the effect of changing in material characteristics with changing in temperature and moisture on buckling capacity and natural frequency of plates with different end conditions and biaxial loading was evaluated. In addition, the effect of delamination of layers on buckling load and natural frequency of plate was studied in different situations. The finite strip method was used in present paper to calculate the critical load of plate considering first-order shear deformation theory. In finite strip formulation for evaluating the displacement field of each strip, the trigonometric shape functions were used in longitudinal direction and the Hermitian and linear shape functions were used for out-of-plane and in-plane transverse direction, respectively. The place and dimension of delaminating layers was modelled by separating the adjacent elements and reconstructing the standard, geometric, force and mass matrices, so, the critical load and natural frequency of laminated plates was calculated in different configurations.