Comparison of physical aging effects on the tension and compression creep of the IM7/K3B composite

Experimental and analytical methods were used to investigate the similarities and differences of the effects of physical aging on creep compliance of IM7/K3B composite loaded in tension and compression. Two matrix dominated loading modes, shear and transverse, were investigated for two load cases, tension and compression. The tests, run over a range of sub-glass transition temperatures, provided material constants, material master curves and aging related parameters. Comparing results from the short-term data indicated that although trends in the data with respect to aging time and aging temperature are similar, differences exist due to load direction and mode. An analytical model was used for predicting long-term behavior using short-term data as input. This model worked equally as well for the tension or compression loaded cases and provided more accurate long term predictions for the shear mode as compared to the transverse mode.