Fiber Bragg Grating Sensor Technology Applied Research In The Dynamic Weighing

With the densification of the traffic way, especially highway's network these years, the phenomenon of overrun and overload is becoming seriously common, which has affected the normal use of roads and bridges, and caused tremendous loss to the country and society. Regardless of that, traditional systems of vehicle weighing can hardly meet the need of modern industry and engineering. Therefore, the research on systems of vehicle weighing which has swift response, highly precision and enduring stability is quite exigent. On account of the high safety, efficiency, precision and stability,fiber grating is qualified to be satisfactory sensor in road and bridge weighing systems. A plated-typed weigh-in-motion (WIM) system based on fiber bragg grating (FBG) is designed in this paper. Experiments, both in the lab and on the spot, are conducted accordingly to test its comprehensive performances.The fatigue performance of the elastic steel plate and the adhesive layer of the weigh-in-motion system is studied as key point. The work and conclusions accomplished in the paper are as follows:1.Considering strain and temperature, the sensing property of FBG is elaborated, the weighing principle of plate-typed weighing system is deduced. The hardware and software design, as well as the detail verification are pressed through modal analysis.2.Experiment of static load in the lab and dynamic load on the spot on the weigh-in-motion system are conducted. The results indicate the strain output shows good linearity with the surface load, and thus can reflect the mass of vehicles passed by.3.Research on fatigue of the elastic steel plate and the adhesive layer of the WIM system are carried out through fatigue test. According to the result, permanent crack appears on the surface of the elastic plate after 2million times of high level stress, and the Loctite 326 structural adhesive shows better fatigue performance compared with w-30502 brittle adhesive.Therefore, it's critical to choose elastic plate and adhesive of good fatigue performance for the endurance and stability of WIM system based on FGB.4. The formation condition, function theories, involved factors, and damage of adhesive are illustrated, and a material test is conducted to test respective shear strength. The result indicates that improving measurements regarding to physical and chemical factors involved with adhesive strength can reinforce adhesive strength to some extent.