Approximate Analysis of the Temperature Induced Stresses and Deformations of Composite Shells

Abstract

In this paper simple formulas are presented which can be used to estimate the response of composite plates and shells to hygrothermal loads. The layup of the shell can be arbitrary (i.e., it can be symmetric or unsymmetric, balanced or unbalanced). The formulas serve two purposes. First, they can be used to calculate directly the stresses, strains, and displacements caused by a temperature and a moisture gradient. Second, the formulas can be used to determine the“effective”thermal and moisture expansion coefficients which are the parameters needed in more accurate numerical (FEM) calculations. The accuracies of the approximate formulas were assessed by sample problems. In these problems the hygrothermal deformations of cylinders and cylindrical segments were calculated by the present approximate formulas and by an exact, three-dimensional analysis. The results of the exact and approximate methods were compared. These comparisons showed that the approximate formulas yield the deformations with a high degree of accuracy.