Hydrobushing Model for Multi-Body Simulations

Abstract: The purpose of this Master’s thesis is to establish a methodology for hydrobushing modelling and parameter identification. The studied hydrobushing is used as a connector element between suspension components in Volvo S60, S80, V70, and XC70. The hydrobushing has coupled amplitude and frequency dependence. At Volvo Cars there is a need for a component model, which fully captures this property. Experimental tests have been performed at the Materials Centre laboratory at Volvo Cars, and this data is used to establish the hydrobushing model. The model consists of one non-linear spring, several fluid elements and elasto-plastic elements coupled in parallel. An automatic fitting procedure finds the set of model parameter values that gives the best fit of the calculated response to the experimental data. The fitting procedure is based on hysteresis fitting, where each calculated data point in a hysteresis loop is compared to the corresponding experimental one and the deviation is minimized. In the validation process it turns out that the hydrobushing model, however, is not able to completely capture the coupled amplitude and frequency dependence of the component. The model is seen to underestimate the damping for dynamic loading at small amplitudes ( ≤ 0.2 mm). Dynamic loading at amplitudes larger than 0.2 mm, as well as static and quasi-static loading, are represented in a satisfying way.