Based on the theory of fiber Bragg grating sensing,and using a 2 m plane stress material model of the simulation experiment,the wavelength shift regulations of fi- ber Bragg gratings under rock settlement deformation ...Based on the theory of fiber Bragg grating sensing,and using a 2 m plane stress material model of the simulation experiment,the wavelength shift regulations of fi- ber Bragg gratings under rock settlement deformation conditions were got,which provided reliable basis for the design of the wavelength bandwidth of sensing gratings.The wave- length increase when the rock layers are under tension,and decrease under compression. Compressive strain sensitivity is bigger than tensile strain sensitivity when the load is lower.However compressive strain sensitivity is smaller than tensile strain sensitivity when the load is higher.Experimental result coincides well with theory.The wavelength band- width of two neighboring fiber Bragg gratings of the gratings used for monitoring the de- formation of rock layer should be no less than 6 nm.An effective new approach for de- tecting the deformation of rock settlement with fiber Bragg gratings is provided.展开更多
Presented the fiber Bragg grating(FBG)sensors for rock strain monitoring inthe 1.2 m long plane stress model of the simulation experiment.In the past,for the lack ofappropriate technique to measure the deformation of ...Presented the fiber Bragg grating(FBG)sensors for rock strain monitoring inthe 1.2 m long plane stress model of the simulation experiment.In the past,for the lack ofappropriate technique to measure the deformation of rock structures,the measurement ofdeflection was restricted to just a few discrete points along rock,and the measuring pointswere limited to the location installed with displacement transducers.We developed amethod to monitor the deformation of rock structures using fiber optical Bragg gratingstrain sensors.The sensors were embedded in rock layers of simulatioh experiment be-fore the materials were put in.These sensors were then used to monitor the experiencedstrain with different face advancing distance.The test results indicate that,if properly in-stalled,FBG sensors can survive under severe conditions associated with embedmentprocess and yield accurate measurements of strains response.At the same time,wemake com parisons of the data obtained by FBG sensors with those by centesimal gauge.The interest in FBG sensors was motivated by the potential advantages that they can offermore than existing sensing technologies.展开更多
基金the National Natural Science Foundation of China(50775060)
文摘Based on the theory of fiber Bragg grating sensing,and using a 2 m plane stress material model of the simulation experiment,the wavelength shift regulations of fi- ber Bragg gratings under rock settlement deformation conditions were got,which provided reliable basis for the design of the wavelength bandwidth of sensing gratings.The wave- length increase when the rock layers are under tension,and decrease under compression. Compressive strain sensitivity is bigger than tensile strain sensitivity when the load is lower.However compressive strain sensitivity is smaller than tensile strain sensitivity when the load is higher.Experimental result coincides well with theory.The wavelength band- width of two neighboring fiber Bragg gratings of the gratings used for monitoring the de- formation of rock layer should be no less than 6 nm.An effective new approach for de- tecting the deformation of rock settlement with fiber Bragg gratings is provided.
基金National Natural Science Foundation of PRC(50374055)Shaanxi Key Lab of Ground Control(02JS43)
文摘Presented the fiber Bragg grating(FBG)sensors for rock strain monitoring inthe 1.2 m long plane stress model of the simulation experiment.In the past,for the lack ofappropriate technique to measure the deformation of rock structures,the measurement ofdeflection was restricted to just a few discrete points along rock,and the measuring pointswere limited to the location installed with displacement transducers.We developed amethod to monitor the deformation of rock structures using fiber optical Bragg gratingstrain sensors.The sensors were embedded in rock layers of simulatioh experiment be-fore the materials were put in.These sensors were then used to monitor the experiencedstrain with different face advancing distance.The test results indicate that,if properly in-stalled,FBG sensors can survive under severe conditions associated with embedmentprocess and yield accurate measurements of strains response.At the same time,wemake com parisons of the data obtained by FBG sensors with those by centesimal gauge.The interest in FBG sensors was motivated by the potential advantages that they can offermore than existing sensing technologies.
