IDENTIFICATION OF FATIGUE CRACKS IN THIN-WALLED BEAMS SUBJECTED TO INITIAL LOADS BY MEANS OF THE NON-LINEAR DYNAMIC ANALYSIS.

Patricia Neri Dominguez¹; Víctor Hugo Cortínez²

¹ Universidad Nacional del Sur; ² Universidad Tecnológica Nacional

doi:10.20906/CPS/CILAMCE2015-0779

Resumo

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.

Palavras-chave: FATIGUE CRACKS; NON-LINEAR DYNAMIC ANALYSIS; THIN-WALLED BEAMS