Distributed Fibre Optic Sensor-Based Continuous Strain Measurement along Semicircular Paths Using Strain...

Area of Science:

• Engineering
• Materials Science
• Sensor Technology

Background:

• Distributed fibre optic sensors (DFOS) are crucial for structural health monitoring, offering continuous spatial strain data.
• Optical fibres are often installed along curved paths, common in large infrastructure.
• Strain measurements from curved DFOS configurations lack validation tools, leading to their exclusion in analyses.

Purpose of the Study:

• To develop and validate an analytical strain transformation equation for DFOS data along semicircular paths.
• To enable accurate strain validation for curved DFOS installations in structural health monitoring.
• To integrate numerical simulation results with experimental DFOS measurements.

Main Methods:

• Developed an analytical equation to transform horizontal and vertical strain components into tangential strain along a curved path.
• Validated the equation numerically using finite element analysis and experimentally using strain rosettes.
• Compared transformed strain values with experimental DFOS measurements on a steel specimen under tensile and flexural loading.

Main Results:

• The proposed strain transformation equation accurately converts measured strain components into tangential strain for semicircular DFOS paths.
• Numerical and experimental validation confirmed the equation's efficacy in tensile and flexural loading scenarios.
• Localized damage to the DFOS coating was found not to affect sensor functionality at other locations.

Conclusions:

• A validated strain transformation equation is presented, enabling accurate analysis of DFOS data from curved paths.
• This method expands the applicability of DFOS in structural health monitoring by validating previously ignored curved path measurements.
• The findings facilitate more comprehensive spatial strain analysis in large engineering structures.