Reconstructing arbitrary strain distributions within fiber gratings by time-frequency signal analysis

Area of Science:

• Optical Engineering
• Materials Science
• Signal Processing

Background:

• Fiber Bragg gratings (FBGs) are widely used in sensing applications.
• Accurate strain measurement in FBGs is crucial for structural health monitoring and other fields.
• Existing methods may have limitations in reconstructing complex strain profiles.

Purpose of the Study:

• To develop and validate a new method for reconstructing arbitrary axial strain distributions along a fiber grating.
• To overcome limitations of existing techniques regarding strain profile complexity and grating length.

Main Methods:

• Application of time-frequency signal analysis techniques.
• Analysis of the reflection spectral response of the fiber grating.
• Reconstruction of axial strain distributions based on spectral data.

Main Results:

• Successful recovery of arbitrary axial strain distributions from spectral responses.
• Demonstrated accuracy and validity of the proposed method.
• Accurate reconstruction of nonmonotonic strain profiles, including constant sections, high gradient variations, and discontinuities.

Conclusions:

• The developed time-frequency signal analysis technique enables accurate and unrestricted strain reconstruction in fiber gratings.
• This method offers a robust solution for analyzing complex strain fields in FBG sensors.
• The technique has potential applications in advanced sensing and structural monitoring.