Evaluation of the material constants of nitrile butadiene rubbers (NBRs) with different carbon black loading (CB): FE-simulation and experimental

In this paper, the experimental data of the mechanical properties of NBR with different carbon black loading (CB) have been determined through tension, compression and relaxation tests. Nonlinear mechanical behaviors of the rubbers are described by strain energy functions in order to guarantee that rigid body motions play no role in the constitutive law. The mathematical models are based on the existence of strain energy density functions, W, to be the scalar potential that depends on the component of the right Cauchy-Green deformation tensor or Green's strain tensor. The experimental data are fitted to these models in order to find the rubber material constants. Visco-hyperelasticity behavior is generated by fitting the experimental data provided from standard quasi-static tests (tensile, compression) and will be applied to determine the material constants. While standard relaxation tests are used for obtaining the scalar multipliers and relaxation time constants. A comparison between the experimental load/displacement response and finite element (FE)-analysis of a uniaxial compression test at different CB loading is presented.