Design And Research Of High Sensitivity FBG Pressure Sensors

Long-term monitoring system consisting of the traditional electrical sensor not only expensive,and the indicators such as stability,durability,and corrosion resistance is poorer,has not well meet the needs of the project for a long time;Fiber Bragg grating as a new type all fiber passive components get eager attention gradually.For fiber Bragg grating pressure sensor,however,most of the limitations in the practical engineering application is stronger,so designed a high sensitivity,good repeatability,linearity and high sensitivity of pressure sensor with high performance indicators is essential to the structure of intelligent real-time health monitoring.On the basis of theoretical research of fiber Bragg grating pressure sensor,two kinds of high sensitivity fiber Bragg grating pressure sensors are designed:Leveraged and arched FBG Pressure Sensor,in order to improve the sensitivity,linearity,repeatability,hysteresis and drift,the work principle and sensitivity of high sensitivity fiber grating pressure sensor are derived and analyzed.Among them,the leveraged high sensitivity fiber grating pressure sensor use of leverage to change the direction of the force,increase the size of the force,stretching the elastic element,the fiber grating measured strain becomes large,so as to force the sensitizer.Using aluminum and steel sheet contrast to two kinds of elastic material,within the scope of the pressure of 0?700 n experimental studies were carried out,draw a tensile aluminum fiber Bragg grating pressure sensor sensitivity of conclusions;At the same time,through to the tensile elastic element in finite element simulation,verified the accuracy of the test.Arch FBG pressure sensor utilizes arches and small elastic modulus material combined measure longitudinal pressure.By pressure into the longitudinal axial stress on the fiber grating to solve the problem will be difficult in practice longitudinal pressure applied directly to the fiber grating.Research also selected elastic material copper,finite element simulation to verify the accuracy of the test.By comparing these two high-sensitivity sensor,it can be drawn:in certain other conditions,the tensile modulus of elasticity of the elastic element is smaller,the higher sensitivity;the use of"structure" sensitizing technology,rather than the traditional packaging technology sensitizing,can effectively increase the sensitivity of the sensor;intermediate conveyance force structure should be as simple as possible,thereby reducing unnecessary accumulation of errors;Sensor structure of elastic element material and the size of the different decisions of the fiber Bragg grating sensor sensitivity;The choice of structural materials affect the service life of sensors,stability,repeatability and so on.The research results will help expand the scope of application of fiber grating technology to improve the degree of complexity of fiber grating pressure sensor,to improve its long-term stability.