Case Study by Nonlinear FEM Analysis for Impact Compression Fatigue Damage in Polypropylene Type Elastomer Damper

The case study by nonlinear FEM analysis for impact compression fatigue damage in polypropylene type elastomer damper was carried out to construct the shape optimum mech.-design of impact absorbing elastomer. Impact compression fatigue test was carried out to investigate the characteristics and damage of erastomer damper. And nonlinear FEM analysis by popular CAE was carried out to examine the distribution of stress and strain of dampers. Main results were as follows ; (1) Examination of the sectional view of tested damper revealed the presence of spherical discoloration damage parts whose diameter was about 1.5 mm. (2) From fractography with using scanning electron microscopy (SEM), it was understood that the form inside the discoloration damage part was granular. It was suggested that one of this cause was the melting of erastomer by temperature rise which depends on strain energy changing into heat energy. (3) At Load-Displacement curve, close agreement between calculated value by nonlinear FEM analysis and compression load test results value was obtained. (4) The position of damage parts within the damper by impact compression fatigue test was almost the same as that of a highest strain part which was calculated by nonlinear FEM analysis.