Instability characteristics of variable stiffness laminated composite curved panels under non-uniform periodic excitation

The instability characteristics of variable stiffness laminated composite (VSLC) shell panels subjected to non-uniform in-plane periodic excitations are explored in the present article. The non-constant orientation of fiber angle in the VSLC panel induces non-uniform stress distributions within the shell panel under uniform as well as non-uniform in-plane loadings. Initially, the pre-buckling stress distributions within the shell panels are evaluated by minimizing the membrane strain energy. Subsequently, a displacement based Ritz method is employed to obtain the matrix representation of the governing equations for static and dynamic instability problems. Bolotin's method is used to determine the dynamic instability regions. The numerical results depicted in the article show the influence of fiber angle orientations, non-uniform distribution of in-plane loadings and damping on the dynamic instability characteristics of VSLC shell panels.