Research On Magnetostrictive Biomimetic Sensor For Water Scouring Monitoring Of Hydropower Station Dam

The safety of the dam plays an important role in ensuring the safety of the hydropower station.The impact of water flow erosion and road load changes on the dam has long-term and real-time performance.Monitoring is more complicated by conventional sensors,and it's hard to experiment by using the conventional method to detect the damage.Therefore,inspired by animal bionics,and based on the Villari effect,this paper designs a magnetostrictive bioinspired whisker sensor with a simple structure,high sensitivity and long life.The sensor can generate a warning signal when the dam is threatened by natural disasters such as earthquakes,mudslides and floods.,and it can effectively improve the safety of hydropower stations.In this paper,the parameters of various magnetostrictive materials are compared,it is found that the Fe-Ga alloy(Galfenol)is the ideal material to make the sensor,because Galfenol not only has a large magnetostriction coefficient,but also has good mechanical properties(rollable).The prototype of the bioinspired whisker sensor was designed and fabricated,and its working principle and the role of each component were explained.And the vibration mode,magnetic field and stress of the sensor Galfenol cantilever beam were analyzed by finite element software.Based on the Euler-Bernoulli beam equation and the piezomagnetic equation,the mathematical model of static sensitivity,dynamic sensitivity and resolution of the bioinspired whisker sensor is constructed.With the Tesla meter,when the Hall sensor is 2mm from the through hole and the permanent magnet is about 12 mm from the through hole,the difference in magnetic induction is the largest.Static and dynamic experimental platform for magnetostrictive bioinspired whisker sensors was built using laboratory instruments to simulate underwater experiments.The experimental results show that the magnetostrictive bioinspired whisker sensor can detect static and dynamic data and can be applied to the scouring monitoring of hydropower dams.The static test results show that it has better linearity and the density is 2.2mV/mN,when its left and right deflection distance is 22 mm,the output voltage is 636 mV and 447 mV respectively.The dynamic test results show that when the excitation frequency is 3.5Hz and 40 Hz,the sensitivity reaches the first peak(2.6mV/mN)and the second peak(4.19mV/mN)respectively,and the resolutions are 0.18 mm and 0.06 mm respectively.Optimized and improved for the original design of the bioinspired whisker sensor that cannot resolve the deflection or stress direction defects.A novel magnetostrictive bioinspired whisker sensor with a dual-wafer composite cantilever structure is designed and fabricated.The bioinspired whisker sensor uses a dual Hall sensor to monitor changes in the magnetic field.A mathematical model of a new magnetostrictive bioinspired whisker sensor was constructed,and static and obstacle sensing experimental platform was built.The experimental results show that the new magnetostrictive bioinspired whisker sensor can distinguish the direction of deflection or stress.When it is deflected to the left and right by 22 mm,its output voltage is 230 mV and 240 mV,respectively,and the average sensitivity of the sensor to the deflection distance is about 10.9mV/mm,the average sensitivity to stress is about 11.42mN/mV,resolution is about 9.8mN/2mV.Through the paper,the characteristics and working principle of magnetostrictive bioinspired whisker have been further understood,which provides some references for the development and application of magnetostrictive bioinspired whisker sensor in hydropower station dam water scour monitoring.The magnetostrictive bioinspired whisker sensor has a certain application value.