Repair of composite laminates-I: Test results

Tests were conducted with the objective of evaluating the effectiveness of techniques used for repairing damaged fiber reinforced laminated composites. Effectiveness of the repair was assessed by the tensile strength of the repaired laminate. In the tests the failure loads of laminates repaired either by the scarf, the uniform lap, or the stepped lap technique were measured. Data were generated with the following parameters having been varied: type of material of the damaged laminate, type of repair material, scarf angle and number of external plies in scarf repair, length and number of repair plies in uniform and stepped lap repair, moisture content of the laminate prior to repair: moisture content of the laminate after repair, test temperature, roughness of grinding tool used in preparing the repair surface, and the temperature applied during the cure of the repair patch. The aforementioned parameters were varied over wide ranges resulting in systematic sets of data which shed light on the influence of each of these parameters on the effectiveness of the repair.