Damping: A Sensitive Structural Property for Damage Detection

Abstract

Data from vibration measurements opens a way to damage assessment by correlating changes in system dynamic parameters with damage indicators. Most methods proposed in the literature are based on the measurement of natural frequencies or modal shapes and modelling damage as local reduction in structural stiffness. In some particular applications these methods, however, have several practical limitations on account of their low sensitivity to damage. This paper shows that damping can be used as a damage-sensitive system property and presents a procedure for instantaneous natural frequencies and damping identification from free vibration response using the wavelet transform. Experimental and simulated examples show that in the structures analyzed damage causes important variations of damping parameters.