Statistical evaluation of experimental and numerical data of stick–slip effects in harmonically excited systems

Abstract

The trend towards lightweight in the automotive industry give rise to new challenges when assessing the influence of material replacements on stick–slip effects. These effects may lead to new acoustic phenomena when aluminium is applied, e.g. coming from the interfaces of the wheel assembly between the rim, brake disk hat and the wheel carrier. Detecting the key influencing parameters is an important task to avoid undesired noises or wear. Whereas self-excited oscillators were intensively discussed in the last decades, much fewer studies about harmonically excited systems were published. The goal of this study is to investigate the effect of different parameters on the stick–slip behaviour of a harmonically excited oscillator exposed to friction. Based on a statistical evaluation of huge experimental data sets with stick–slip effects, a two-degree-of-freedom model for the frictional testing machine is proposed and implemented with several friction models. These models are compared with respect to their ability to fit the measurement data and their computational effort. Numerical parameter studies including a huge amount of different parameter sets are performed to determine the effect of several parameters on the limit cycle of the dynamic system, quantified by the number of stops per cycle. The influence of more complex friction laws on the parameter maps are discussed in relation to the published results by Hong and Liu as well as Papangelo and Ciavarella.