Identification of fatigue cracks in Thin-Walled Beams subjected to initial loads, by means of the non-linear dynamic analysis

VÍCTOR H. CORTÍNEZ; PATRICIA N. DOMÍNGUEZ

Río de Janeiro

Congreso; XXXVI Ibero-Latin American Congress on Computational Methods in Engineering (CILAMCE 2015); 2015

Many structural systems are designed as thin-walled beams. Sometimes, these structures may suffer fatigue damage generated by dynamic loadings. It is important the early crack identification in order to avoid a catastrophic global failure. In this paper a methodology for identifying fatigue cracks in thin-walled beams, by measuring dynamic displacements, is developed. This approach is based on a theoretical model for the forced non linear vibration of this kind of structures, taking into account the breathing effect of the cracks and the existence of initial stresses. The identification problem consists in obtaining the depth and location of a fatigue crack in order to minimize the relative difference between theoretical and experimental displacement values.