Uma proposta de identificação de defeito em estrutura tipo viga baseada nas frequências naturais e modos de vibrar.

Abstract

This investigation aims to evaluate the modal properties, especially the natural frequencies and vibration modes, as elements of a proposal for identification of defects in beam-type structures. This new procedure for defect identification comprises the following steps: the evaluation of the changes in natural frequencies of the structure due to the defect, the selection of the main modes for defect identification; obtention of the natural frequency behavior associated with preferential modes versus the severity of defect calculated via model and defect identification by the observation of this curve and variations of natural frequency profiles. The research is numerical and experimental and the structure is a aluminum beam. Defect has been identified by the proposed method and also by a technique based on Fractal Theory for comparison. The results showed that the proposed methodology is promising for defects identification in beam structures.