High Temperature Eddy Current Sensor for Real-Time Structural Health Monitoring of Critical Engineering Components

Real-time structural health monitoring (SHM) of engineering components exposed to high temperature and pressure is an utmost need. The hostile operating conditions such as elevated temperatures, contraction/expansion, vibrations, etc., may lead to catastrophic failure due to creep, thermo-mechanical fatigue or environmental attack (oxidation and hot corrosion). Non-availability of sensors susceptible at high temperature (HT) is a reason to handicap assessment and monitoring of such degradation during operation. Sensors using micro-fabricated sensing element are the promising, non-contact technology that have significant potential in structural health monitoring of critical engineering components operated at elevated temperatures. The present paper addresses this issue by developing application specific high-temperature sensors for real-time condition monitoring of the components operated at high temperature. The goal is to provide superior performance for in situ material condition monitoring (material degradation, flaw detection, stress relaxation, and/or creep monitoring) and through-wall temperature measurement. The sensor consists of a micro-fabricated primary (drive) winding and a secondary winding adjacent to the primary for sensing the response to a material under test. Multiple coils are cascaded/stacked together to increase the SNR and sensitivity of the sensor. The effectiveness of the proposed technique is first demonstrated on synthetic dataset from an eddy current simulation model. Further work is being underway for addressing the issues at elevated temperature.