Estimating Coulomb and Viscous Friction From Free-Vibration Decrements

Abstract

This study introduces an algorithm for the simultaneous estimation of Coulomb and viscous damping effects from free-vibration decrements in a damped linear single degree-of-freedom (DOF) mass-spring system. Numerical and experimental estimations are included. The algorithm complements existing ideas for the estimation of either viscous or Coulomb as the sole damping source in a system. Analysis shows that both damping effects can indeed be separated. Numerical study of a combined-damping system demonstrates a perfect match between the simulation parameters and the estimated values. Experimental study includes two types of real systems. Experimental results illustrate the reliability of this method. An analysis provides conservative bounds on different estimations errors.