This article presents two theoretical approaches that simulate the visco-elastic behaviour of elastomer specimens. The first approach, based on an equivalent rheological model, provides a dynamic modulus extracted from a Volterra development of the visco-elastic constitutive law using either relaxation or creep kernels. The second approach establishes a restoring force model based on a first-order differential equation that relates the restoring force to the deflection, the forcing frequency and deflection amplitude dependence being taken into account by the envelope curves of the force-deflection loop. The two models proposed are first applied to an elastomer cylinder mount made of a small quantity of carbon black filler and then to elastomer plates made of a large quantity of black filler. The cylinder and plates specimens are subjected to traction-compression and shear tests, respectively. In order to compare the two approaches, the dynamic modulus of the second approach is extracted by applying classical formulae to the force-deflection loop obtained with the restoring force model. Moreover experimental investigations permit comparing the simulated and measured dynamic modulus and validating the two theoretical approaches proposed.