Thermal Stress Evaluation of a Symmetrically Laminated Composite Plate.

摘要

The purpose of this investigation is to determine the in-plane thermal stresses for a symmetrically laminated, 50 xl2 xO.19 composite plate with temperature dependent material properties. For this study only in-plane stresses are investigated. The in-plane equations of motion are solved exactly using a stress function, and the resulting compatibility equation is solved approximately using the Galerkin method. Ibis investigation also serves as proof of concept for the variational method. This method produces accurate results while being less rigorous in a computational sense than the high degree of freedom finite element model required to solve the same problem. Variations with lamina orientation and multiple layered laminates are investigated. Results are given in terms of the in-plane force resultant. The baseline case for this study was aluminum and the in-plane force resultant at the center of the plate was calculated to be 60.251 lb/in. The exact solution for the in-plane force resultant at the center of the plate is 59.667 lb/in, a difference of less than 1 percent. Based on these results additional investigations were accomplished for composite plates. The results from this study will be used as parametric data by NASA-Dryden in verifying finite-element codes and will aid in experimental analysis of thermal loading on composite plates. Furthermore, this study should serve as a reference to an investigation that considers thermally stressed laminates with bending and extensional coupling.