Modeling of the deformation behavior of polymer composites at high strain rates and at elevated temperatures

The deformation behavior of two commercial polymer composite roll cover materials was studied at high and intermediate strain rates to simulate the nip loading in paper machine applications. For the high strain rate testing, Split Hopkinson Pressure Bar (SHPB) technique was applied as the intermediate strain rate tests were made using servohydraulic materials testing machines. Both types of tests were also conducted at elevated temperatures. To the results of intermediate strain rate tests, simple viscoelastic models were fitted to evaluate recovery behavior of the materials. The determined creep rates, especially at higher stresses and temperatures, suggest that for relatively long duration pulses the deformation accumulation may occur leading to possible damage of the cover material. The results on SHPB, however, suggest that when the loading pulses are short enough, full recovery of the deformation can be expected within the available time between compression cycles.