Damping: A Sensitive Structural Property for Damage Detection

CURADELLI, OSCAR; RIERA, JORGE; AMBROSINI, DANIEL; AMANI, MARTA

Córdoba. Argentina.

Congreso; XVI Congreso sobre Métodos Numéricos y sus Aplicaciones y I Congreso de Matemática Aplicada, Computacional e Industrial. ENIEF-MACI.; 2007

Asociación Argentina de Mecánica Computacional y Univ. Nac. de Córdoba.

The vibration measurement approach to damage assessment consists in correlating changes in system dynamic parameters with damage indicators. The most of the methods proposed in the literature are based on the measurements of natural frequencies or modal shapes and modeling of damage as local reduction in structural stiffness. In many applications these methods, however, have significant practical limitations because of their low sensibility to damage.  This paper shows that damping can be used as damage-sensitive feature 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 the structures analyzed present little natural frequency shifts with damage but, pronounced variations of damping.