In-Plane Shear Testing of Medium and High Modules Woven Graphite Fiber Reinforced/Polyimide Composities

摘要

Iosipescu shear tests were performed at room temperature and at 316 degrees C (600 degrees F) on woven composites with either M40J or M60J graphite fibers and PMR-II-50 polyimide resin matrix. The composites were tested as supplied and after thermo-cycling, with the thermo-cycled composites being tested under dry and wet conditions. Acoustic emission (AE) was monitoried during the room and high temperature Iosipescu experiments. The shear stresses at the maximum loads and the shear stresses at the significant onset of AE were determined for the composites as a function of temperature and conditioning. The combined effects of thermo-cycling and moisture on the strength and stiffness properties of the composites were evaluated.