A Study on Fracture Behaviour of Polycarbonate at High Temperature (1st Report, Dependency on Fracture Toughness Evaluation at Mode I)

Abstract

High polymer materials are remarkably weak to heat compared with the metal and ceramics. And, there is a limit in the use of high polymer materials as parts of the structure. Therefore, to expand the range of use of high polymer materials further, the strength evaluation by the high temperature environment is needed. In this study, the polycarbonate was examined as a sample material about static and dynamic fracture behaviors in the high temperature environment. The stress intensity factor was determined by using method of caustics. An environmental temperatures ware assumed to be a room temperature, 40, 60, 80, and 100°C. The crack model assumed V-notch, and aimed at the union of the specimen configurations. As a result, the stress intensity factor indicated a small value by the temperature high. The same the vibration behavior of the dynamic stress intensity factor by which the temperature change is accompanied has been understood. As for static and dynamic fracture toughness values, the tendency which decreased gradually along with the rise of the temperature was obtained. It has been understood that the difference of dry processing of the specimen greatly exerts the influence from static by the dynamic fracture behavior.