Prediction of strain rate sensitivity of high density polyethylene using integral transform of dynamic mechanical analysis data

- A method to predict strain rate sensitivity in modulus based on DMA data.
- Integral transform is used to relate storage modulus to elastic modulus.
- Predictions from the method are validated against experiments in literature.
- The method allows obtaining modulus at various strain rates from one specimen.

Recent interest in understanding the effect of strain rate on mechanical properties has motivated this study to develop a correlation between frequency domain dynamic mechanical analysis (DMA) results and elastic modulus values that are obtained from a separate set of elaborate tensile tests conducted over a wide range of strain rates. Using the time-temperature superposition principle and the integral relations of viscoelasticity, the DMA results are converted into a time-domain relaxation function in order to predict the strain-rate dependent modulus. The transformation technique is validated with experimental results for high density polyethylene (HDPE) resin and is found to be accurate over a wide range of strain rates. Cross correlation between DMA results and tensile test results over a wide range of strain rates can help in substantially reducing the requirement for tests that are needed to characterize the material behavior with respect to strain rates, temperature and loading frequency.

239