A Statistical Approach for Assessing Reliability for Impedance-based Structural Health Monitoring Using Probability of Detection

摘要

The Impedance-based Structural Health Monitoring (ISHM) technique has become a promising and attractive tool for damage identification in the field of nondestructive evaluation techniques. This method takes into account the variations of the electromechanical impedance (EMI) of the structure as caused by the presence of damage by using piezoelectric transducers bonded on the structure surface (or embedded into it). However, temperature effects are a critical challenge to a practical implementation of an ISHM system. In this technique, the EMI, which is directly related to the mechanical impedance of the structure, is obtained as a frequency domain dynamic response. Based on the variation of the impedance signals, the presence of damage can be detected. In this work, a reliability assessment is performed on a monitored structured (aircraft Al panel) aiming at determining threshold indexes associated with damage. The diagnostic, which is obtained from a statistics-based methodology, uses a temperature compensated damage metric in order to simulate a structure in its actual operational conditions.