PileSense: Innovative ultrasonic guided wave technology for intelligent sensing of defects in steel sheet pile infrastructure
Structural steel is the material of choice for the vast majority of structures in coastal and offshore locations due to its combination of durability, ease of fabrication and ability to provide a relatively cost-effective solution. However despite its many benefits, steel is prone to corrosion, which is the principal cause of deterioration in steel, waterfront structures.
PileSense is an innovative, non-destructive testing (NDT) solution for corrosion sensing in steel piles, in particular, those sited in marine environments. It is an ultrasonic guided wave (UGW) based, remote sensing system that offers rapid and smart assessment of steel piles. The project’s solution overcomes limitations in current state-of-the-art inspection systems, which are rudimentary and labour intensive, and revolutionises the detection of corrosion in steel piles for infrastructure operators and inspection companies.
The PileSense consortium partners developed the remote corrosion sensing symstem as completely portable, cost-effective and non-invasive, with the ability to provide a quick and accurate representation of the steel sheet piles that marine infrastructure systems are so dependent upon. Some of the technical barriers to overcome included addressing small "interaction-anomalies" between the guided-waves and the profiled edges of each pile section, discovered during trials. Unique finite element analysis (FEA) models were applied in order to understand the wave-propagation within the steel-piling and defect detection. A new, ultrasonic transducer array and attachment mechanism for the sheet-piling forms a core part of the innovative system and advanced signal processing algorithms deliver optimum, automated, defect detection capability.
Within the project, Brunel Innovation Centre (BIC) studied guided wave properties in corrugated sheet piles, including the interactions between corrugated surfaces and flat surfaces on the piles, and the coupling between sea water and sheet piles. The significant corrosion arising from accelerated-low-water-corrosion as a result of each pile being immersed in sea water, and the influence of water on wave propagation characteristics, and part of the wave being reflected by the pile-water interface, were also studied by BIC. In addition, the Centre worked on signal processing techniques to eliminate reflection from known edges on the pile. This cleaned up the signal so that interpretation of it would be easier, providing the basis for further signal processing algorithms to be investigated for their ability to improve signal to noise ratio.
The PileSense solution enables earlier identification of corrosion, leading to life extension of structures through being able to undertake more timely repairs before damage is too great. Therefore, each PileSense system will reduce the overall cost of steel-pile inspection by an estimated £172k/km, helping to mitigate the very expensive costs associated with purchasing and installing steel piles.
Partners: Transmission Dynamics and BIC (Brunel University London and TWI)
PileSense received funding from Innovate UK.