The compressive mechanical properties and constitutive relation of polyurethane elastomer

摘要

In order to describe the mechanical property of polyurethane elastomer (PU elastomer) under quasi-static compression, we have adopted universal tester of South JingKe electronics to proceed with equivalent static compression for polyurethane elastomer material, and studied the mechanical behavior of PU elastomer under the rate of 1.2mm/min, namely the corresponding strain rate 10~(-2)/s. The results show that: when the strain is between 0 and 0.2, the slope of curve decreases with increasing strain, and the variable quantity is extremely small; between 0.2 and 0.6, it continues to increase with increasing strain, presenting the feature of up concave and showing hardening phenomenon; and it maintains rubber elasticity in the entire deformation process. In order to get reasonable constitutive model of PU elastomer, we also need to meet the conditions of large compressive deformation, the Neo-Hookea model, Mooney-Rivilin model, Yeoh strain-energy function, improving Mooney-Rivilin model and James-Green-Simpson form was choose which matching of experimental data, finally obtain the constitutive model of PU elastomer material under quasi-static compression, and determine the stress-strain relation.