A novel criterion for crack identification in beam-like structures using distributed piezoelectric sensor and controlled moving load

Abstract

The present study addresses the problem of crack identification in beam-like structures using a distributed piezoelectric sensor and controlled moving load. First, governing equations for the vibration of a cracked Timoshenko beam integrated with a piezoelectric layer and subjected to a moving load are established and their solution in the frequency domain is derived and acknowledged as electro-mechanical response of the beam. Then, variation of the electro-mechanical frequency response is examined versus crack and moving load parameters with the aim to propose a novel indicator, called herein spectral assurance criterion, for crack detection in beam-like structures. Finally, a procedure is developed for crack identification from moving load-induced frequency response measured by the distributed piezoelectric sensor based on the proposed spectral assurance criterion. The numerical analysis demonstrates that (a) the piezoelectric layer can be used as a distributed sensor for reliably measuring the mechanical response of beam subjected to moving load; (b) the speed-controlled moving harmonic force is a useful tool for exciting a beam-like structure for its health monitoring purpose and (c) the proposed spectral assurance criterion is actually a novel and efficient indicator for crack identification in beam-like structures.