Experimental Evaluation of the Effect of Hole Fabrication/Treatment Techniques onResidual Strength and Fatigue Life of Polycarbonate Specimens with Holes

摘要

An experimental test program was conducted to evaluate different techniques offabricating/treating holes in extruded polycarbonate. This program included surface finish evaluation and tension-tension fatigue and tensile residual strength testing of polycarbonate specimens with open holes. Eight different hole fabrication/treatment techniques were developed, including drilling (several variations), step drilling, entry and exit radiusing, solvent polishing, shot peening, and cold working. The differences in tensile residual strength for the specimens with holes was minimal; however, fatigue life varied by as much as a factor of ten between the best technique, cold working, and the worst, chemical polishing. In addition, limited testing indicated that annealing extruded polycarbonate decreases fatigue life by eliminating favorable residual surface compressive stresses. Polycarbonate, Hole drilling, Fabrication, Surface roughness, Treatment, Cold working, Shot peening, Fatigue testing, Tensile testing.