Reliability Modeling And Analysis Of Wind Turbine Blade Fatigue Test System Based On Multi-fiber Grating

Wind turbine blades are one of the most critical core components of wind turbines.They play a vital role in the efficiency and operational safety of wind turbines.Blades are generally tested by static tests,fatigue tests,and other type tests to ensure their design quality and high reliability.Sensors are an important tool for wind power blade fatigue testing systems.The accuracy and accuracy of the measurement data are effective assessments of wind power blade safety Important guarantee.Although the fiber Bragg grating(Fibber Bragg Gratting,FBG)sensor has many advantages such as high sensitivity,anti-corrosion,anti-electromagnetic interference,and wavelength coding,etc.,the bare FBG must be encapsulated and protected during use.The FBG needs to be pasted and connected in series to enter the test system paper.For the strain measurement in the wind blade fatigue test,the FBG sensor is packaged and pasted in the sensor system,and the uncertainty band of the material and process when multiple sensors are connected.For the unreliability problem,the reliability modeling and analysis of FBG sensor packaging process,sensor adhesive type,connection method,and other aspects were carried out.The main research content of the paper includes the following aspects:First,analyze the composition of the FBG-based wind blade fatigue test system,determine the links that affect the reliability of the sensor,treat each link as a typical series structure link,and establish a reliability model based on the wind blade fatigue test system;Failure Mode and Effect Analysis(FMEA),analyzes all possible failure modes of each component in the system and all possible effects on the system,combined with Fault Tree Analysis(FTA),analysis The occurrence probability and impact degree of each bottom event of the system define weights.Second,study the impact of FBG sensor packaging technology on its reliability,design a special hot-press mold,develop Glass Fiber Reinforced Plastics(GFRP)encapsulated GFRP/FBG sensor,and develop the GFRP/FBG The strain sensing performance of the sensor is tested;then,the reliability model of a single GFRP/FBG sensor is established.Third,study the influence of assembly process on the reliability of the wind turbine blade fatigue test system.Consider the factors such as the width and thickness of the packaging material when developing GFRP/FBG,the surface roughness of the sample after fabrication,and the adhesive during installation,which affect the system reliability due to the attenuation of the strain transfer rate of the GFRP/FBG strain sensor.Through experiments,we study the difference in optical power loss between the GFRP/FBG connected in series through the flange and welding,the exchange of the two ends of the GFRP/FBG sensor into the optical path,and the number of GFRP/FBG sensors effectively connected in series on a fiber impact on system reliability,respectively.Fourth,studying the impact of environmental factors on the reliability of the blade fatigue test system,and use four-point bending fatigue tests to conduct high and low temperature and humid heat tests on the packaged GFRP/FBG samples to obtain the fatigue performance degradation rules of the developed GFRP/FBG sensor.