Accurate non-linear calculation model for decoupling thermal and mechanical loading effects in the OBR measurements

Area of Science:

• Optoelectronics
• Materials Science
• Sensor Technology

Background:

• Fiber optic sensors are vital for condition monitoring in aerospace, energy storage, and medical industries.
• Current methods struggle to decouple spectral shifts caused by simultaneous strain and temperature variations.
• Linear temperature models introduce significant errors in high-temperature environments.

Purpose of the Study:

• To develop and validate a high-precision method for discriminating strain and temperature using fiber optic sensing.
• To address the limitations of linear models in accurately calculating temperature effects.
• To improve the reliability of optical fiber sensor data under combined mechanical and thermal loading.

Main Methods:

• Derivation of a novel, physics-based non-linear temperature formula.
• Validation using Rayleigh backscattering Optical Backscatter Reflectometry (OBR) measurements.
• Detailed analysis of the coupled strain and temperature effects.

Main Results:

• The new non-linear temperature formula significantly enhances accuracy in strain and temperature discrimination.
• The developed calculation approach demonstrates improved performance over an extended temperature range.
• Accurate decoupling of spectral shifts caused by pure mechanical strain and thermal loading is achieved.

Conclusions:

• The validated non-linear temperature formula provides a breakthrough for precise fiber optic sensor signal interpretation.
• This advancement is crucial for reliable condition monitoring in demanding industrial applications.
• The study offers a robust method for analyzing complex strain-temperature interactions in optical fibers.