The Research Of Component Structural Damage Based On Impedance Analysis Technic

Elcectro-mechnical impedance technology is a very prospect new technique of nondestructive examination. The technique utilizing piezoelectric material's direct and converse piezoelectric effect, it's characteristic to be used as both driver and sensor, through detecting and contrasting the impedance of piezoelectric ceramic sheet of before and after damage to realize damage diagnosis. This paper makes a study of structure damage detecting and analysis utilizing piezoelectricity intelligent material's electro-mechanical impedance characteristic.This article firstly introduced electro-mechanical impedance technique's unique advantage (that is particularly adequate for detecting tiny damage) using in structure nondestructive examination and health monitor. It deduced the relation between structure mechanical impedance based on electromechanical coupling effect and PZT electrical impedance. Subsequently make analysis and experimental verification to it using finite element analysis method. Making piezo-electric analysis of single PZT and PZT pasted in the aluminum beam about impedance/admittance spectra, impedance real part/impedance imaginary part spectra, admittance real part/admittance imaginary part spectra, and contrasted to the corresponding experimental result. It educed that the result gotten by ANSYS finite element analysis method agree well with experiment result in spectra trend, peak value and frequency of peaks. Lastly had some research in simulative practical working condition and design experiment utilizing its characteristic. Include:Impedance response experiment, free beam crack damage experiment, fixed beam crack damage experiment, bolt loose and tight experiment, the influence of measurement result caused by PZT position experiment and load experiment. And made determination for each damage using damage index, demonstrate that the electro-mechanical impedance technique is a good method of nondestructive examination, Made some analysis for load designing experiment, it needs further study to obtain preferable outcome.Researches demonstrated that electro-mechanical impedance technique can do well in damage detecting and determination, but as a new technique it is still in the laboratory study stage, it remains to do abundant experimental research, particularly in data processing, finite element analysis and simulating practical conditions, and so on.