Stress And Strain Analysis And Experimental Study Of The Rotating Blades Based On Measurements By Fiber Bragg

In this paper,the writer mainly through building the model of electric fan blade backward by CAD software and then transport the model of the fan blades to finite element analysis software for stress and strain,growth of fatigue crack and the life of the fan blades.By contrast the test of high-speed operation of the fan blades for its stress distribution and Fatigue Characteristics by of the grating sensor.Building the CAD model reversely based on image data,the measurement data of the physical measurement which will be put through the pro/e for re-modeling,CAD platform in order to restore "physical appearance"(kind of reproduction parts model). Then the model generated by Pro/e the will be put into the ANSYS for analyzing their stress and strain,fatigue crack growth and life expectancy in strict accordance with the rotation fan blade the boundary conditions of.Thus the distribution of stress and fatigue crack of the fan will be clear which can provide a theoretical reference for the next step of the grating sensor testing laboratory after the layout and design optimization in future.First,it gave a briefing on research methods of the fan blade and talks about the background and significance of the subjects.Secondly,introduce the theoretical basis for finite element analysis,a brief introduction of the paper work must be finite element analysis of the theoretical knowledge and Fatigue life analysis of theoretical approaches such as nominal stress method,the local stress-strain law,as well as crack propagation in fracture mechanics such as the YU crack model.Thirdly,design the model of electric fan blade backward by CAD software which will be used for finite element analysis and analyze of the stress-strain and fatigue life,the crack growth of the fan blade by ANSYS10.0.Then the fatigue life curve(S-N curve),and crack growth rate and stress curves(da / dn-S curve) was painted in accordance with the results of the analysis of FEA.And the same time, make the experimental study,using the grating blade sensor in the high-speed rotation for test the size of the stress,fatigue life. Finally,the finite element analysis results and the results of experimental data were compared to determine the risk place of fan.if they are both agreed which will also prove the reliability of measuring the stress and strain rotating blades by the grating sensor.The third chapter,Chapterâ…£andâ…¤,is the focus of papers.By grating blade testing laboratory has been in the actual functioning under stress size,crack growth under the stress distribution and fatigue life.The results of finite element analysis and the results obtained by the grating testing laboratory are consistent with each other,particularly in the size and distribution of stress on the fan surface.So we get the risk place and fatigue life-span of a high-speed rotating fan blades which incline to have a fatigue crack.Further,we can identify the main factors which impacts most of fatigue life of a high-speed rotating blades that is local stress concentration,but also verify the feasibility of grating measurement and The reliability of reverse built.All this will provides a theoretical basis for the optimal design and on-line monitoring in some day.