Analytical model of critical thrust force for exi-ply delamination during drilling: thermo-mechanical analysis

International audienceDrilling induced delamination has been recognized as a major problem during drilling of composite materials. In the literature, it has been shown the delamination located at the hole exit is related to the thrust force generated during the drilling process. In this context, the influence of temperature of machining on the critical thrust force responsible for delamiantion at the hole exit is investigated. For this, an analytical model considering thermo-elastic field equations has been established with the aim of predicting the critical thrust force. The validation of this model has been conducted at room temperature via punching tests carried out on carbon fibre epoxy multi-directional composite laminates. Some difference in predictions exists which are mainly attributed to the variability in ply thicknesses due to the manufacturing process. Such an analysis underscores the need to explicitly account for machining temperature effects for the prediction of the critical thrust force responsible of the delamination