CREEP AND PHYSICAL AGING IN A POLYMERIC COMPOSITE - COMPARISON OF TENSION AND COMPRESSION

To help address the lack of engineering data on the time-dependent beh avior of advanced polymeric composites, a combined experimental and an alytical research program was initiated to investigate the similaritie s and differences of the effects of physical aging on creep compliance of IM7/K3B composite loaded in tension and compression. Recently deve loped novel experimental apparatus and methods were employed to test t wo matrix dominated loading modes, shear and transverse, for two load cases, tension and compression. The tests, run over a range of sub-gla ss transition temperatures, provided material constants, material mast er curves and aging related parameters. Assessment of these new result s indicated that although trends in the data with respect to aging tim e and aging temperature are similar, differences exist due to load dir ection and mode. An analytical model proposed previously by the author s for tension loading was used for predicting long-term tension and co mpression behavior using short-term data as input. These new studies i ndicated that the model worked equally as well for the tension or comp ression loaded cases. Comparison of the loading modes indicated that t he predictive model provided more accurate long-term predictions for t he shear mode as compared to the transverse mode. Parametric studies s howed the usefulness of the predictive model as a tool for investigati ng long-term performance and compliance acceleration due to temperatur e.