Temperature Effects on Ultimate Bearing Strength of Polymeric Composite Joints

Abstract

The ultimate bearing strength (UBS) of IM7/PETI-5 composite materials in a quasi-isotropic lay-up, 64 plies thick, was determined using a compressive bearing test setup. Testing was performed at room temperature, 177°C (350°F) and −50°C (−58°F). Some specimens were thermally aged at 177°C (350°F) for up to 10000 h. It was found that the IM7/PETI-5 composite material's UBS was essentially unaffected by the thermal aging. At elevated temperature, the UBS of IM7/PETI-5 decreased, while at low temperature, the UBS increased slightly. Despite the increase in UBS at low temperature, the bearing failure was catastrophic, resulting in widespread delamination due to the brittleness of the matrix.