A shear horizontal phased array steering excitation technique for remnant wall thickness quantification

Area of Science:

• Non-destructive testing
• Ultrasonic guided waves
• Structural health monitoring

Background:

• Accurate wall loss quantification is crucial for maintaining structural integrity in pipes and plates.
• Limited access to components presents significant challenges for traditional inspection methods.
• Catastrophic failures can be avoided with timely maintenance informed by precise wall thickness data.

Purpose of the Study:

• To develop and validate a novel technique for precise wall loss quantification in structures.
• To utilize the cut-off frequency of mode SH1 for accurate defect assessment.
• To enhance defect detection capabilities for critical infrastructure.

Main Methods:

• A novel guided wave phased array steering technique was developed for exciting shear horizontal waves (SH1).
• The influence of array parameters (length, pitch, element width) on SH1 excitation was investigated.
• Mode SH1 was dynamically excited over a wide frequency-wavelength range using phased array element control.

Main Results:

• Simulations demonstrated accurate quantification of a 65% wall thinning defect, a 15% improvement over established techniques.
• The directionality of SH1 was studied for optimized quantification under various conditions.
• Experimental validation using an EMAT and synthetic steering confirmed the technique's efficacy on defects.

Conclusions:

• The developed phased array steering technique offers a promising approach for accurate and rapid wall loss quantification.
• This method significantly improves the detection of severe wall loss defects (above 50%).
• The technique holds potential for enhanced structural health monitoring and maintenance planning.