Monitoring of mining induced subsidence through measurement of ground strains with Fiber Bragg Grating sensors
In this paper the application of Fiber Bragg Grating based sensors for the monitoring of mining induced subsidence phenomena is illustrated. A high number of sensors were installed in the pavement of a major highway thanks to the use of Bragg Grating arrays encapsulated in composite rods. The sensors and the associated demodulation equipment provide continuous measurements and allow the immediate implementation of safety measures by the authorities responsible for the highway.
Fibre Optic Sensing Based Slope Crest Tension Crack Monitoring System for Surface Mines
The stability of slopes in surface mines is of high concern due to the risk to both personnel and excavation plant. A variety of slope stability monitoring systems have been developed and implemented in the industry in order to predict slope failures before they occur and to minimise the damage to peopleand plant. This paper examines the technical challenges of the current slope tension crack monitoringsystems and demonstrates the feasibility of an innovative FBG-based crack sensing system. The results of preliminary experiments show that with the application of the mechanical displacement converter, the slope crack generation can be measured using FBG strain sensors.
A Close Look at the Embedment of Optical Fibers into Composite Structures
A way in which to control vibrations at the tip of a flexible beam prompted this research. Polyimide coated multi-mode optical fibers were embedded between layers of the composite beam in order to measure strain as the beam is deformed. A close look at the embedment of the optical fibers between layers of preimpregnated unidirectional carbon fiber tape after cure is shown, and the results discussed. Mechanical tests were performed on composite specimens with embedded optical fibers and photographs of embedded optical fibers after the mechanical tests were performed are shown in detail.