Experimental determination of residual stresses in composite laminates [0 2 / θ 2 ] s

International audienceThe present work aims to determine the residual stresses in carbon fiber/epoxy composite laminates, by means of the incremental hole-drilling method. Based on mechanical theories of composite laminates and an elastic plate with a circular hole, the relationship between the relaxed strains on the surface of laminates and the residual stresses in laminates was established. This newly deduced theoretical formula was adapted into the incremental hole-drilling method and allowed us to further study the residual stresses in the through-thickness direction for various composite laminates. Related numerical modeling of composite laminate with a hole was built to calibrate the coefficients within the formula. Experiments were conducted and the residual stresses in composite laminates [02/θ2]s are presented. The proposed approach was validated with the consistence between our results for cross-ply laminates and those in literature