Design, Calibration, and Application of a Wide-Range Fiber Bragg Grating Strain Sensor

Area of Science:

• Structural Health Monitoring
• Mechanical Engineering
• Materials Science

Background:

• Infrastructure safety is critical, especially during catastrophic events.
• Existing strain sensors struggle with monitoring extreme deformations.
• Accurate strain measurement is vital for structural integrity.

Purpose of the Study:

• To develop a wide-range strain sensor for monitoring large structural deformations.
• To enhance the safety analysis of critical infrastructures like bridges and pipelines.
• To overcome limitations of conventional sensors in extreme strain scenarios.

Main Methods:

• A snake spring desensitization mechanism was designed and its axial stiffness derived using strain energy.
• The mechanism was fabricated using 3D printing and integrated with a fiber Bragg grating (FBG) sensor.
• The assembled wide-range sensor underwent calibration and pipeline testing.

Main Results:

• The developed sensor achieved a wide strain range of 10,000 με.
• A linearity coefficient exceeding 0.9995 was recorded, indicating high accuracy.
• Successful testing in a pipeline demonstrated effective real-time monitoring capabilities.

Conclusions:

• The proposed wide-range FBG strain sensor effectively addresses the challenge of monitoring large structural strains.
• This technology offers a reliable solution for real-time structural safety analysis of critical infrastructures.
• The sensor's performance indicates its potential for widespread application in monitoring infrastructure under extreme conditions.