Measurement of Microstructural Damage in Cylindrical Components using Guided Waves
Creep damage in high temperature pipes is a significant challenge to industry as it involves high value components whose integrity is critical to safety. This project aims to develop a novel Guided Wave Testing (GWT) method capable of detecting microstructural material damage, such as creep, on in service components. GWT is an established method of Non-Destructive Evaluation (NDE), which is used worldwide for the inspection of petrochemical and power station components, primarily pipelines. Its principal attraction is that it can inspect the full volume of the material of the components very rapidly. Recent observations in the field have shown that GWT signals can be affected, albeit slightly, by creep damage of the components. This is unexpected, and not understood; nevertheless the possibility to use GWT to detect such damage, which could be done without interrupting operation of the plant, would be enormously attractive for the management of a whole range of high-value components. A key first challenge of the research project will be to identify exactly what is happening when the GWT signals are affected by the damaged material. This will involve investigations in materials science, guided wave theory, experiments, and model simulations. Modelling of microstructural defects in a course grained material presents a significant computational challenge and previous work within Imperial College London has led to the development of the finite element software Pogo which will allow the intensive simulations to be undertaken. The outcome will be to identify understanding of the phenomena, the best guided wave mode and frequency for the inspection, and the sensitivity relationship of the GWT signals to the extent of the material damage. GWT instrumentation and procedures will then be developed to exploit this knowledge, thus bringing this new capability into use in industry.
Funding Sources and Sponsors
EPSRC EP/L015587/1. (EPSRC Centre for Doctoral Training in Quantitative NDE) Guided Ultrasonics LTD
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