Fault detection in a rotating shaft by using the electromechanical impedance method and a temperature compensation approach
Aldemir Cavalini Jr1; Denise Oliveira1; Diogo Rabelo1; Roberto Neto1; Valder Steffen Jr1
1 Federal University of Uberlândia (UFU), School of Mechanical Engineering (FEMEC)
doi:10.20906/CPS/CILAMCE2015-0381
Resumo
The aim of this paper relies on the correct detection of incipient faults in rotating shafts by using the so-called electromechanical impedance method. Basically, this structural health monitoring technique - SHM monitors changes in the electric impedance of piezoelectric transducers bonded to (or embedded into) the host structure, through specific mathematic equations, the so-called damage metrics, to detect damage. This is possible once the electrical impedance of the transducer is directly related to the mechanical impedance of the structure. Previously, successful experimental tests were performed in a horizontal rotor supported by roller bearings in which PZT patches were bonded along the host structure. Although successful, the obtained results shown to be susceptible to changes in the environmental and machine temperatures. Aiming at overcoming the limitations faced, in this contribution a compensation technique is proposed. The variations on the measured impedance signatures are minimized by using a heuristic optimization method associated with different damage metrics. The results from different compensation techniques are presented for comparison purposes.
Palavras-chave: fault detection; electromechanical impedance method; temperature compensation; rotating shafts