Real-time monitoring of bolt clamping force at high temperatures using metal-packaged regenerated fiber Bragg grating sensors. (May 2019)

• Record Type: Journal Article
• Authors: Tu, Yun; Huang, Yong-Kuo; Tu, Shan-Tung
• Is Part Of: International journal of pressure vessels and piping. Volume 172(2019)
• Page Start: 119
• Page End: 126
• Publication Date: 2019-05
• Subjects: Bolted joint -- Clamping force -- Regenerated fiber Bragg grating -- High temperature -- Structural health monitoring; Pressure vessels -- Periodicals; Pipe -- Periodicals; Récipients sous pression -- Périodiques; Tuyaux -- Périodiques; Pipe; Pressure vessels; Periodicals; 681.76041
• DOI: 10.1016/j.ijpvp.2019.03.006
• Languages: English
• ISSNs: 0308-0161

Abstract

Abstract: Inappropriate clamping force in bolted flange joints operated at high temperatures has been regarded as the main issue that endangers the reliability and safety of a plant. In order to accurately and reliably measure the bolt clamping force, an innovative technique is proposed using metal-packaged fiber Bragg grating (RFBG) sensors. A metal-packaged RFBG sensor is developed by a combination of magnetron sputtering and electroplating followed by spot-welding on a bolt, and calibrated by uniaxial tensile and thermal tests. The clamping force in a bolted steel-steel joint is monitored by the metal-packaged RFBG sensor spot-welded on the bolt and analyzed by a finite element model. The sensor exhibits good linear response to axial loads applied to the bolt when exposed to constant high temperatures up to 500 °C, as well as good stability and repeatability. Its thermal response is non-linear and can be expressed as a cubic-polynomial function of temperature. The variation of the clamping force in the bolted joint subjected to thermal loading is then monitored by the sensor, which is further verified by a comparison of the experimental results and the numerical predictions showing a satisfactory agreement. The results demonstrate that this technique provides a new possibility for real-time monitoring of bolt clamping force and structural health monitoring of bolt joint structures operating in high-temperature environments.