Distributed strain monitoring for bridges: temperature effects

Author(s):  
Ryan Regier ◽  
Neil A. Hoult
2019 ◽  
Vol 189 ◽  
pp. 580-588
Author(s):  
Sara Nurmi ◽  
Neil A. Hoult ◽  
Simon D. Howell

2011 ◽  
Vol 340 ◽  
pp. 136-142
Author(s):  
You Long Gao ◽  
Guang Li Xu ◽  
Jun Yi Zhang ◽  
Qi Lang Le

Because of the temperature effect of the distributed strain observation, it is not easy to analyze the real strain in tested data. Experiments of fibers under different temperatures and force conditions are carried out. The bare fiber, Φ 0.9 SM and Φ 2.0 SM single-mode sleeve fibers are chosen in the experiment scheme. It was found that the temperature effect of the distributed strain is independent with the force condition. The additional strain of fibers under the stress and different temperatures are discussed. For practices using, temperature correction equations on single-mode sleeve fiber are proposed to reduce the temperature effect.


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
S. Delepine-Lesoille ◽  
X. Phéron ◽  
J. Bertrand ◽  
G. Pilorget ◽  
G. Hermand ◽  
...  

Temperature and strain monitoring will be implemented in the envisioned French geological repository for high- and intermediate-level long-lived nuclear wastes. Raman and Brillouin scatterings in optical fibers are efficient industrial methods to provide distributed temperature and strain measurements. Gamma radiation and hydrogen release from nuclear wastes can however affect the measurements. An industrial qualification process is successfully proposed and implemented. Induced measurement uncertainties and their physical origins are quantified. The optical fiber composition influence is assessed. Based on radiation-hard fibers and carbon-primary coatings, we showed that the proposed system can provide accurate temperature and strain measurements up to 0.5 MGy and 100% hydrogen concentration in the atmosphere, over 200 m distance range. The selected system was successfully implemented in the Andra underground laboratory, in one-to-one scale mockup of future cells, into concrete liners. We demonstrated the efficiency of simultaneous Raman and Brillouin scattering measurements to provide both strain and temperature distributed measurements. We showed that 1.3 μm working wavelength is in favor of hazardous environment monitoring.


Optik ◽  
2021 ◽  
pp. 168113
Author(s):  
Yage Zhan ◽  
Ziting Wang ◽  
Min Han ◽  
Long Xu ◽  
Zhongkang Song ◽  
...  

Author(s):  
L. S. Lin ◽  
K. P. Gumz ◽  
A. V. Karg ◽  
C. C. Law

Carbon and temperature effects on carbide formation in the carburized zone of M50NiL are of great importance because they can be used to control surface properties of bearings. A series of homogeneous alloys (with M50NiL as base composition) containing various levels of carbon in the range of 0.15% to 1.5% (in wt.%) and heat treated at temperatures between 650°C to 1100°C were selected for characterizations. Eleven samples were chosen for carbide characterization and chemical analysis and their identifications are listed in Table 1.Five different carbides consisting of M6C, M2C, M7C3 and M23C6 were found in all eleven samples examined as shown in Table 1. M6C carbides (with least carbon) were found to be the major carbide in low carbon alloys (<0.3% C) and their amounts decreased as the carbon content increased. In sample C (0.3% C), most particles (95%) encountered were M6C carbide with a particle sizes range between 0.05 to 0.25 um. The M6C carbide are enriched in both Mo and Fe and have a fee structure with lattice parameter a=1.105 nm (Figure 1).


Sign in / Sign up

Export Citation Format

Share Document