Phase Plane Analysis and Determination of Damping Limit in Mechanical Systems with Stick-Slip 2015-36-0026
In the field of engineering, there is a well known phenomenon called “stick-slip” a specific type of vibration in a mechanical system where friction is involved, it is qualified as non-linear, auto-excited and generally stable within a limited cycle.
During stick-slip, the behavior of the friction coefficient as a function of the sliding velocity has big influence on the wave pattern, wherein various models can be found in the literature. Besides affecting wave patterns, this behavior affects significantly the amount of damping necessary to reach an asymptotic level of stability.
The objective of this work is to study various friction models found in literature, for example: constant transition between coefficients, linear and exponential and apply these models in mechanical systems that represent brake systems.
The determination of damping required to minimize vibration is performed by a process of numerical optimization, using a software with a user friendly template developed especially to achieve this objective, this allows for a quick and easy change of parameters.
Data from the dynamic behavior of a vehicular brake needs to be compared against the simulation. The simulation parameters are adjusted to determine the friction behavior of measured vibrations. Using these adjustments, it becomes possible to determine the necessary amount/quantity of damping to suppress the vibration.