Residual Stresses in Polymer Matrix Composite Laminates

Abstract

Residual stresses in composites are induced during fabrication and by environmental exposure. The theory formulated can describe the shrinkage commonly observed after a thermal expansion test. Comparison between the analysis and experimental data for [02 /± 45] s laminates of various material systems indicates that the residual stress-free temperature can be lower than the curing temperature, depending on the curing process. Ef fects of residual stresses on ply failure including the acoustic emission characteristics are discussed.