Nondestructive testing and 3D imaging of PE pipes using terahertz frequency-modulated continuous wave

Area of Science:

• Materials Science
• Non-Destructive Testing
• Terahertz Technology

Background:

• Polyethylene (PE) pipes are critical for natural gas transport, necessitating reliable inspection methods.
• Conventional inspection techniques for PE pipes have limitations in detecting internal defects.

Purpose of the Study:

• To develop a novel terahertz (THz) three-dimensional imaging system for nondestructive inspection of PE pipes.
• To enhance the safety and integrity assessment of natural gas transportation infrastructure.

Main Methods:

• Design and implementation of a THz three-dimensional imaging system utilizing frequency-modulated continuous-wave (FMCW) technology.
• Utilizing a THz source with a bandwidth of 0.225-0.330 THz and output power >5 mW for submillimeter resolution.
• Integration of a deep-learning-based THz transformer network for intelligent defect identification.

Main Results:

• The THz FMCW system successfully performed nondestructive testing and 3D imaging of various defects in PE pipes.
• Achieved submillimeter spatial resolution in three dimensions for detailed defect visualization.
• Intelligent defect identification using the deep-learning model reached an accuracy rate of up to 88%.

Conclusions:

• The developed THz FMCW system offers a promising solution for nondestructive inspection of PE pipes.
• This technology provides technical guidance for real-world applications and improves upon traditional detection methods.
• The study highlights the potential of THz imaging and AI for enhancing natural gas pipeline safety.