Study On Repeatability、Consistency And Fatigue Properties Of Adhensive Packaged FBG Strain Sensors

By virtue of their small size, light weight,immunity to electromagneticinterference signals,low loss,long-distance transmission and other advantages,FBGcan be widely used in aerospace,ship,electric power,petro-chemical,and various civilengineering fields. However,the fiber Bragg grating has its shortcomings,that is it’sslender, fragile, so it must be encapsulated in actual project.There are a variety offiber gratings’ packages,which the most common package is epoxy adhesive paste,ifthe packaged FBG sensors used in long-term complexd hostile environment, theymay produce different degrees of damage,so the FBG sensors’ performanceparameters are affected. In actual engineering practice, there often need a number ofFBG sensors,so it’s important to study the problem of duplicate consistency betweendifferent sensors.If the sensors are long-term used in high temperature environment,the temperature performance of adhensive FBG sensors’ cannot be ignored. In thework process,the fiber Bragg grating sensors may be subjected to frequent tension andcompression,however,the anti-fatigue properties of FBG sensors directly affect theirlife,so the study of adhesive packaged FBG responses under fatigue problem is veryimportant. In this paper,take the most commonly adhesive packaged FBG sensors asthe research object,studied the FBG sensors’ repeatability and consistency,temperatureaging resistance and vibration fatigue performance problems.Based on the two typesof adhesives packaged FBG strain sensors to carry out these three performanceparameters’ corresponding test questions, research and analysis the sensors. The maincontents are as follows:1. Introduce the development of FBG sensing technology and its basic principles,packaging technology and adhensive packaged FBG sensors’ strain transfercharacteristic.2. Combined with the specific use, studied different adhesives packaged FBGstrain sensors’ repeatability and consistency problems. A Program was developed inaccordance with detailed tests study, the results showed that：the strain responsetesting, EPO-TEK-353ND plastic packaging FBG strain sensors’ repeat consistenc isbelow the Ante solid epoxy glue’s performance; the temperature response testing, EPO-TEK-353ND’s srepeat consistency is slightly higher than the solid epoxy glue.3. The Ante solid epoxy glue packaged FBG strain sensors are implemented intemperature aging test,and introduced specific experimental methods. The test resultsshowed that：after a number of different temperatures cycles and prolonged aging,theFBG sensors’ performance are not significantly reduced.4. Two FBGs were symmetrically pasted on the surfaces of equal intensity beam,the vibration fatigue tests were carried out by analyzing the strain sensitivity changesin different vibrational times of equal beams.Test data shows that after38×106timesvibration,the beam’s sensitivity decreased, but its use performance such as thestrength of the beam is not affected.And the adhesive’s surface has no falling off,cracks and other phenomena.