Ultrasonic inspection of studs (bolts) using dynamic predictive deconvolution and wave shaping

Area of Science:

• Nuclear Engineering
• Materials Science
• Non-Destructive Testing

Background:

• Bolt degradation poses significant risks in the nuclear industry, with undetected cracks leading to potential disasters.
• Stud bolt inspection is challenging due to complex component geometries.

Purpose of the Study:

• To develop an effective method for detecting and sizing small cracks in nuclear stud bolt threads.
• To address the limitations of current inspection techniques for critical components.

Main Methods:

• Utilizing mode-converted Rayleigh waves that propagate along crack faces.
• Analyzing the delayed arrival of a specific wave pulse between regular thread reflections.
• Employing digital signal processing techniques: wave shaping and dynamic predictive deconvolution.

Main Results:

• A distinct delayed pulse indicates the presence of a crack.
• The delay time of this pulse is proportional to the crack's size.
• Proposed signal processing methods enhance the detection of these slow Rayleigh waves.

Conclusions:

• The presented method offers a viable solution for early crack detection in stud bolts.
• Accurate crack sizing is achievable by measuring Rayleigh wave propagation time.
• Advanced signal processing is key to overcoming detection challenges in complex structures.