Characterization methods for strain‐induced damage in polypropylene

Abstract Various methods are used to characterize the deterioration of mechanical properties in polymers. The focus is set on distinguishing between time‐dependent and irreversible damage two different grades polypropylene. First, digital image correlation utilized capture stress–strain behavior during monotonic tensile tests. Changes specimen volume recorded throughout experiment serve as an indicator for crazes voids. However, elastic modulus, E , cannot be monitored entire experiment. Further analysis performed form cyclic load–unload residual strain, ε res a function applied appl obtained each cycle. Results show that primarily suffers from tested polymers this case. Subsequently, alternative technique applied, where specimens prestrained then allowed relax. In following dynamic analysis, viscoelastic effects can avoided. Considerations onset evolution made. Ultimately, these results confirmed through microcomputed tomography, shapes densities defects captured high resolution.