Hygrothermal stresses and strains in axisymmetric composite shells

Abstract

A numerical procedure is presented for calculating the hygrothermal stresses and strains in laminated composite shells of revolution with axisymmetric temperature and moisture distributions. The procedure is based on a shell theory developed previously by Doxsee, and utilizes a displacement-based finite element method of solution of the governing equations. The stresses and strains in isotropic, orthotropic, and [0/90/0/90] graphite-epoxy composite cylinders were calculated using different levels of approximation for the displacements. The stresses and strains thus obtained were compared to values given by existing analytical solutions. These comparisons illustrate the accuracies of the shell theory and the numerical procedure, and show the importance of selecting the proper approximation for the displacements. The results also demonstrate that transverse shear and transverse normal strains must be taken into account to achieve good accuracy.