Modelagem para simulação e análise numérica do fenômeno Stick-slip em freios a disco

Abstract

The stick-slip tribological phenomenon consists of a noise generation mechanism present in disc brakes and the study of its occurrence is extremely important to improve the comfort of drivers and passengers. Although several models are present in the literature, there is no consensus on which model is closest to real brake systems. The present work is based on the mass-spring model of a degree of freedom, relating it to different transition models between static and dynamic friction coefficients, depending on the relative speed between the surfaces. Thus, this work contributes to this discussion by simulating various transition models between friction coefficients, through the simulation, evaluating the influence of related parameters and comparing the simulations with experimental data found in the literature. The results of the simulations point out the differences between the behavior of the numerical models. The analysis of properties indicates that the stick-slip phenomenon is mitigated by increases in speed and stiffness and by reductions in mass and difference between friction coefficients. The study of form factors points out that transitions with less discontinuities and with very abrupt or very smooth decays also contribute to the less occurrence of the phenomenon. While the comparison of simulations with experimental data suggests that for certain conditions, different models provide more approximate results.