Monitoring Of Ice Structrue Utilizing Smart Optical Fiber Sensor

Ice is a special material that is complex on mechanical behavior and vulnerable to external environmental. There are of great significance on whether the monitoring of actual use of large-scale ice structure or the experimental research of ice mechanics. Aiming at solving the lack of the monitoring means for large-scale ice structure and the shortcomings of the testing means for ice mechanics experiment, a set of optical fiber smart monitoring technology for ice structural monitoring has been studied in this paper, and a kind of optical fiber sensor for ice crack-damage monitoring has also been developed. A variety of ice specimen and small simulative ice sheets have been tested through the application of this technology. The main contents include:Firstly, based on the principle of the optical fiber Bragg grating and optical distributed Brillouin sensing technology and then the effective method of the optical fiber laid in the ice surface and interior, the ice structure optical fiber smart monitoring system has been formed which can achieve a variety of testing purposes, test a variety of scales of ice and effectively grasp the whole structure and the local mechanical behavior.Secondly, a kind of packaged optical fiber crack sensor has been developed by using silicone rubber adhesive and the silane coupling agent, where delicate and easily broken bare-fiber is not appropriate for the large strain in the ice crack-damage monitoring. Then, the mechanical properties and the perceived performance of the packaged optical fiber sensor have been tested. After above, the reduction of its low temperature sensing has been verified and that is reliable and stable on such a large strain testing.Thirdly, based on the ability of collaborative deformation and sensitivity, the bare optical fiber sensor is laid on the ice blocks, ice beam, and the sink-ice for testing. The feasibility of this technology and the superiority as opposed to material testing machine and strain gauge have been verified, as well as the advantages of wide-scale distributed measurement.Finally, in order to study the use state of silicone packaged optical large strain sensor in crack-ice, a theoretical analysis model has been established in ice-silicone non-slip interface conditions. Both the theoretical analysis and the experimental calibration have been used to get the relationship between patulous width of ice crack and fiber optic sensing strain. Considering the drawback of the theoretical assumptions, the theoretical analysis has been modified by results of calibration tests. At last, a laboratory simulation of ice crack-damage monitoring has been done. The test result shows that the crack testing of this kind of sensor is accurate and reliable.