Measurement of Residual Stresses in Layered Composites by Compliance Method

Abstract

Macroscopic residual stresses in layered composites were investigated by paying particular attention to implement a reliable experimental technique for the measurement of through-the-thickness residual stresses in layered composite plates. Residual stresses in (010/9010) S APC-2 laminate have been measured by two experimental techniques, i.e., by layer removal method, and by compliance method. The latter has been successfully employed up to date for the measurement of residual stresses in isotropic materials and the authors propose an extension of the method's use to layered orthotropic composites. The data obtained by the layer removal and compliance methods are compared to the results obtained by a numerical model developed by other researchers. There is an excellent agreement between the experimental data obtained by the layer removal and compliance methods and the results predicted by the model. The layer removal and compliance methods are also compared in terms of accuracy and practicality.