A new chevron electromagnetic acoustic transducer design for generating shear horizontal guided wave

Area of Science:

• Materials Science
• Non-Destructive Testing
• Electromagnetics

Background:

• Guided wave electromagnetic acoustic transducers (EMATs) are crucial for non-destructive testing and structural health monitoring.
• EMATs generate horizontally polarized shear waves for pipeline defect characterization.

Purpose of the Study:

• To propose and evaluate a new Chevron pattern-like coil structure for periodic permanent magnet (PPM) EMATs.
• To enhance the generation of bi-directional shear horizontal waves (SH-waves) and reduce side lobes.

Main Methods:

• A novel Chevron pattern-like coil structure was designed and implemented with a PPM EMAT configuration.
• Three-dimensional Finite Element Method (FEM) modeling and simulation were performed.
• The simulation results were validated through experimental testing.

Main Results:

• The proposed EMAT design effectively generates bi-directional SH-waves with reduced side lobes.
• An optimal Chevron angle was identified for generating orthogonal propagating waveforms, leading to constructive interference.
• The Chevron EMAT demonstrated significant performance improvements compared to conventional racetrack PPM EMATs.

Conclusions:

• The developed Chevron EMAT prototype shows high potential for inspecting surface defects in fuel transportation pipelines.
• This advanced EMAT technology offers improved capabilities for structural health monitoring and non-destructive testing applications.