Nonlinear finite element analysis of laminated composite doubly curved shells in hygrothermal environment

In the present investigation, the geometrically nonlinear analysis of laminated doubly curved shells in a hygrothermal environment is presented using the finite element method. The laminated composite shells may be exposed to moisture and temperature during their service life. Hygrothermal effects induce residual stresses and the laminated shell may undergo large bending deformation. The shell geometry used in the formulation is derived using the orthogonal curvilinear coordinate system. Based on the principle of virtual work the nonlinear finite element equations are derived. A total Lagrangian approach associated to the arc-length method is implemented to solve the equilibrium equations. The present results are found to compare well with those available in the open literature and parametric studies are performed to analyze the nonlinear deflections of [0 degrees/45 degrees/90 degrees](s) laminated spherical, cylindrical and conoidal shell panels under hygrothermal condition.