Identifying Coulomb and viscous damping from free-vibration acceleration decrements

A new damping-identification method for the simultaneous identification of Coulomb and viscous damping effects from free-vibration acceleration decrements in a damped linear single degree-of-freedom (dof) mass-spring system is presented. In deriving the algorithms, the governing differential equations are solved to come up with two schemes separately suitable for viscous and dry-friction damping estimations. Numerical study of a combined-damping system demonstrates a perfect match between the estimated values and the simulation parameters. The method is also applied to an experimental system. Experimental estimates obtained from the proposed method are compared to those obtained using other identification schemes to illustrate the effectiveness and reliability of the new method.