Evaluation of Crack and Corrosion Detection Sensitivity Using Piezoelectric Sensor Arrays (Preprint)

摘要

The use of guided-wave ultrasound has significant potential for structural health monitoring in a number of critical aerospace applications. A key question which needs to be addressed with regard to damage sensing in realistic aircraft structures involves detection sensitivity levels for cracks and corrosion. In this research effort, a systematic evaluation of the detection sensitivity levels of surface-bonded piezoelectric sensor arrays has been undertaken using experimental studies and analytic modeling. A series of reference standards have been developed for variations in crack/corrosion sizes and types from micron to millimeter scales. Both engineered and realistic crack/corrosion conditions have been studied using distributed sensing approaches. In-situ damage initiation and growth studies are also being conducted using dynamic fatigue crack and electrochemical corrosion attack damage mechanisms. Preliminary results are presented for evaluating typical damage detection levels, where opportunities for improving measurement fidelity, quantification, and sensitivity in realistic aircraft structures are considered.