Waveguide Sensing for Structural Health Monitoring at Elevated　Temperatures: Simulating Corrosion Damage Reconstruction

摘要

Ultrasonic transducers typically used for inspection such as wall thickness measurement are not suitable for hightemperature applications and the inspections are more of a periodic and manual in nature instead of continuous. Awaveguide based method combined with synthetic focusing image reconstruction has been proposed for StructuralHealth Monitoring (SHM) of the components operating in hostile environments and is sometimes too complex andinaccessible for manual inspection. This work follows to develop a waveguide based sensing method to implement arobust and accurate monitoring of surface back wall damage with moderate coverage range. Finite Element (FE)Analysis has been carried out to study the multi-modal behavior in waveguides of rectangular cross sectional geometryand to choose optimal mode(s) and geometry which are best suited for the application. Simulations based on 3DElastodynamic and 2D Acoustic FE models has been taken to study and implement the reconstruction for different casesrepresenting various levels of wall loss. The waveguide is being used for transmitting the ultrasonic guided waves intothe structure under investigation and the received signals from the structure has been processed using Synthetic focusingtechnique for the surface back wall reconstruction to access damage caused by corrosion like phenomenon.