Schadensdetektion mithilfe elektromechanischer Impedanzspektren

Within a cooperational project of the University of Siegen between the "Applied Mechanics Group" (ATM) of the Department of Mechanical Engineering and the chair "Steel Construction and Composite Steel Construction" of the Department of Civil Engineering, a new monitoring method for non-destructive damage detection on bolts was developed and tested according to its applicability on real life structures. The method is based on the measurement of electromechanical impedance spectra, which change varying influences on the structure. Therefore this method is suitable for identification of the structural state. The investigation method could be established in the monitoring of bridge structures. The investigations were carried out on threaded bolts welded onto steel plates. In order to determine the general behaviour of the electromechanical impedance spectra of the test specimens under varying conditions, preliminary investigations were carried out. The expected opposite development of the spectra under the influence of varying preloads and saw cuts was determined. The fatigue experiments which were carried out subsequently have shown the applicability on real life structures. In the article first experimental results are presented and the applicability of the measurement methodology for structural monitoring is discussed afterwards.