Low Cycle Fatigue Behavior and Variable Amplitude Fatigue Life Calculations for an SRIM Polymer Matrix Composite
The objective of this research was to determine the feasibility of applying strain based fatigue life calculation models, which are commonly used for metals, to smooth SRIM polymer matrix composite axial specimens subjected to variable amplitude loading. A thorough investigation of the monotonic and strain controlled constant amplitude low cycle fatigue behavior of this material was conducted, including the effects of mean strains/stresses on the fatigue life of smooth specimens. Using these results, mean stress life calculations were made on the constant amplitude tests, as well as on smooth specimens subjected to strain controlled variable amplitude loading, using the Morrow and SWT mean stress models. These results were compared to experimental data, and it was found that the correlation between experimental and calculated lives was very poor, for both the constant amplitude and variable amplitude tests.