A Quantitative Health Monitoring Approach Using Impedance Sensors

Due to the high frequency range employed, the impedance-based technique is very sensitive to minor changes in the near field of piezoelectric sensors. The sensitivity of this technique to local changes is very useful in most cases. However, due to the difficulties in developing an analytical model at such high frequency ranges, this technique can not correlate a change in electrical impedance with a specific change in structural properties, hence it only provides limited information on the nature of damage. In addition, to assess the life expectation of a structure, damage should be quantified and appropriate model is necessary for quantitative evaluation. This research is motivated by the necessity to combine the impedance-based health monitoring with a model-based damage detection technique in order to establish a more rigorous and quantitative health monitoring methodology.