Experimental Characterization and Numerical Modeling of Wire Rope Isolators

Wire rope isolators are non-linear devices which are commonly used to isolate vibrations both during transportation and operation of machineries. Their hysteretic behaviour allows for a relevant damping factor, which guaran-tees a good isolation performance without the need for further damping devices. Nevertheless, the conventional linear spring-damper model is not able to describe the actual component behaviour, so that it cannot be used at design stage. Addi-tionally, mechanical properties provided by the manufacturers are generally par-tial, ambiguous, not rigorous and limited to equivalent stiffness and damping co-efficients. These parameters are generally good to predict the quasi-static behav-iour of the spring, such as the deflection under the component weights. Never-theless, they are not suitable to predict the vibrating behaviour, to describe the hysteresis cycle and to predict the actual filtering capabilities. In this paper, a systematic procedure to experimentally characterize the component behaviour is proposed. The obtained experimental data were then used to fit a numerical model, which was derived by modifying the Bouc-Wen hysteresis model. Inde-pendent experimental data were then compared to numerical results to validate the proposed approach.