title: An Improved Metal-Packaged Strain Sensor Based on A Regenerated Fiber Bragg Grating in Hydrogen-Loaded Boron-Germanium Co-Doped Photosensitive Fiber for High-Temperature Applications.
abstract: Local strain measurements are considered as an effective method for structural health monitoring of high-temperature components, which require accurate, reliable and durable sensors. To develop strain sensors that can be used in higher temperature environments, an improved metal-packaged strain sensor based on a regenerated fiber Bragg grating (RFBG) fabricated in hydrogen (H₂)-loaded boron-germanium (B-Ge) co-doped photosensitive fiber is developed using the process of combining magnetron sputtering and electroplating, addressing the limitation of mechanical strength degradation of silica optical fibers after annealing at a high temperature for regeneration. The regeneration characteristics of the RFBGs and the strain characteristics of the sensor are evaluated. Numerical simulation of the sensor is conducted using a three-dimensional finite element model. Anomalous decay behavior of two regeneration regimes is observed for the FBGs written in H₂-loaded B-Ge co-doped fiber. The strain sensor exhibits good linearity, stability and repeatability when exposed to constant high temperatures of up to 540 °C. A satisfactory agreement is obtained between the experimental and numerical results in strain sensitivity. The results demonstrate that the improved metal-packaged strain sensors based on RFBGs in H₂-loaded B-Ge co-doped fiber provide great potential for high-temperature applications by addressing the issues of mechanical integrity and packaging.
authors.affiliation: Key Laboratory of Pressure Systems and Safety (Ministry of Education), School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, China. ytu@ecust.edu.cn.
authors.forename: Yun
authors.initials: Y
authors.lastname: Tu
authors.affiliation: Laboratory of Smart Materials and Structures, Centre for Advanced Materials Technology, School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney 2006, Australia. lin.ye@sydney.edu.au.
authors.forename: Lin
authors.initials: L
authors.lastname: Ye
authors.affiliation: Key Laboratory of Pressure Systems and Safety (Ministry of Education), School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, China. shpzhou@ecust.edu.cn.
authors.forename: Shao-Ping
authors.initials: SP
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Pressure Systems and Safety (Ministry of Education), School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, China. sttu@ecust.edu.cn.
authors.forename: Shan-Tung
authors.initials: ST
authors.lastname: Tu
keywords: high temperature; metal-packaged; photosensitive fiber; regenerated fiber Bragg grating (RFBG); strain sensor; strength degradation; structural health monitoring