A study on fiber Bragg grating (FBG) strain sensor based on symmetrical lever structure.

Area of Science:

• Mechanical Engineering
• Optical Sensing
• Materials Science

Background:

• Structural health monitoring (SHM) and fault diagnosis of high-end mechanical equipment rely on accurate deformation detection.
• Existing Fiber Bragg Grating (FBG) strain sensors face challenges in effectively measuring thin-walled structure deformations.

Purpose of the Study:

• To develop a novel FBG strain sensor capable of accurately measuring the deformation of thin-walled structures.
• To enhance the sensitivity and stability of FBG strain sensors for improved SHM.

Main Methods:

• Theoretical analysis of sensor sensitivity.
• Finite element analysis using SOLIDWORKS and Abaqus for simulation and optimization.
• Fabrication and experimental testing of the developed FBG sensor.
• Strain testing system setup for performance evaluation.

Main Results:

• The proposed FBG sensor exhibits a sensitivity of approximately 6.6 pm/με, which is 5.5 times greater than that of a bare FBG.
• The sensor demonstrates significantly higher strain measurement sensitivity and stability compared to bare FBG.
• Achieved linearity of over 99% for accurate measurement of minute strains.

Conclusions:

• The developed symmetrical lever-based FBG strain sensor effectively meets the requirements for detecting thin-walled structure deformation.
• The sensor's enhanced sensitivity and stability provide a valuable tool for SHM and fault diagnosis.
• This research offers a reference for developing more sensitive optic-fiber strain sensors.