Analysis of a dry-friction oscillator driven by a stochastic base motion

Roberta Lima¹; Rubens Sampaio¹

¹ PUC-Rio

doi:10.20906/CPS/USM-2016-0011

Resumo

In this paper the dynamics of a dry-friction oscillator driven by a stochastic base motion has been studied. The system consists of a simple oscillator (mass-spring) moving on a base with a rough surface. This roughness induces a dry-frictional force between the mass and the base which is modeled as a Coulomb friction. Besides this, the base has an imposed stochastic bang-bang motion which excites the system in a stochastic way. The non-smooth behavior of the dry-frictional force associated with the non-smooth stochastic base motion induces in the system stochastic stick-slip oscillations. The focus of the paper is to construct a stochastic model to the base motion and to analyze the stick-slip dynamics of the system from a probabilistic view point. Defined a time interval for analysis, the variables of interest are the number of time intervals in which stick and slip occur, the instants at which they begin and their duration. To make a stochastic analysis, these variables are modeled as stochastic objects and Monte Carlo simulations are employed to compute statistics of them.

Palavras-chave: friction-induced vibration; stick-slip; non-smooth system; stick duration; stochastic quantification