Nonlinear approaches regarding mechanical and thermal behaviour of visco-elastic vibration isolators

Abstract

Thermal effects inside the vibration elastomeric isolators have usually been neglected and this aspect can leads to certain differences between simulations and experiments. Continuous damping during the working cycle leads to an internal transfer of energy from mechanical movement to virtually infinitesimal punctual heating sources distributed into the entire isolator volume. This continuous tuning between the dynamics and the damping component can lead both to a stable and to an unstable behaviour in respect with the ratio between the external excitation frequency and the system natural frequency. These phenomena can be dignified through an additional terms added to the governing equations of the vibration isolation system. This paper deals with passive vibration isolation area and presents a set of nonlinear approaches regarding the mechanical and thermal phenomenon inside the elastomeric isolators during the exploitation time. The main idea consists in the continuous functional correlations between thermal and mechanical phenomena, and their influences upon the global dynamic characteristics of vibration isolators. Parametrical expressions were assumed from real experiments, directly or by means of computational techniques. Both lumped parameters model and finite element method simulations were performed in order to validate practical models.