Guided waves in a monopile of an offshore wind turbine

• Published in: Ultrasonics Vol. 51; no. 1; pp. 57 - 64
• Main Authors: Zernov, V., Fradkin, L., Mudge, P.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 2011; Elsevier
• Subjects: Acoustical measurements and instrumentation; Acoustics; Applied sciences; Buildings. Public works; Composite; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Guided waves; Hydraulic constructions; Inspection; Measurement and testing methods; Offshore construction; Offshore structure (platforms, tanks, etc.); Offshore structures; Physics; Shores; Solid mechanics; Structural and continuum mechanics; Structural steels; Transducers; Transduction; acoustical devices for the generation and reproduction of sound; Ultrasonic testing; Wind turbine; Wind turbines; Composite; Wind turbine; Guided waves; Immersed body; Acoustic measurement; Guided wave; Wind generator; Steel; Composite material; Plate; Foundations; Hydroelasticity; Grouting; Ultrasonic control; Pile; Offshore structure; Non destructive test; Ultrasonic transducer; Monitoring
• ISSN: 0041-624X; 1874-9968
• DOI: 10.1016/j.ultras.2010.05.008

We study the guided waves in a structure which consists of two overlapping steel plates, with the overlapping section grouted. This geometry is often encountered in support structures of large industrial offshore constructions, such as wind turbine monopiles. It has been recognized for some time that the guided wave technology offers distinctive advantages for the ultrasonic inspections and health monitoring of structures of this extent. It is demonstrated that there exist advantageous operational regimes of ultrasonic transducers guaranteeing a good inspection range, even when the structures are totally submerged in water, which is a consideration when the wind turbines are deployed off shore.