The mechanical response of elastomers is known for its non-linearity depending on the strain level but also on the strain rate. In this context, the objective of the present Ph.D. thesis is to experimentally characterize the mechanical response of elastomers under dynamic loading and define one (or more) relevant model(s). Tensile and compression tests were carried out at constant true strain rate in order to highlight the influence of strain rate on the material behaviour. New test facilities have been developed because traditional testing methods are not adapted for average strain rates. We have highlighted the stiffening of the material with strain rate as well as the increase in energy dissipation over the range of strain rates considered; it is mainly due to the viscoelastic nature of the material. To model the response of these materials, large strain viscoelastic constitutive equations were investigated. A comparison of the two most widely used approaches, namely integral and differential approaches, is proposed to determine the most suitable one to predict the behaviour of elastomers under average strain rates. The integral approach has been adopted. The parameters of a model of this type have been determined with the help of the tensile tests. Eventually, this law has been implemented in the LS-DYNA code. Validation tests were carried out for different types of loading conditions: tension, compression but also propagation of tensile waves. Those different loading conditions are generally well represented, so simulations of a suspension mount under various loading conditions are proposed; they allow to propose a macro-element that reproduces the overall behaviour of the rubber mount.
