| Wind turbine blade structure is slender and flexible body,and the environment makes it easy to be affected by wind and earthquake load.These loads will make the blades vibrate,which will lead to the destruction of the wind turbine and affect the conversion of wind energy.However,when considering the material of the wind turbine blade,its stiffness should be considered as well as its strength,and the weight of the blade should also be considered.Because of its light weight,high specific strength and strong designability,glass fiber composite material has been widely used in large and mediumsized fan blades.However,in the development trend of large-scale and lightweight fan blades,glass fiber composite materials have begun to reach their performance limits,so carbon fiber composite materials with higher strength are applied to blades.However,as the blades of the wind turbine become larger and larger,the vibration response after being subjected to loads will become larger.Therefore,while developing large blades,the vibration of the wind turbine blades should also be suppressed.Shape Memory alloy(SMA)materials have two unique properties: shape memory effect and superelasticity,which can be activated under high stress and dissipate energy,and thus has been widely studied in the field of vibration control.Therefore,this paper uses ANSYS Workbench finite element software to study the energy dissipation characteristics of shape memory alloy superelasticity,and uses this characteristic to suppress vibration of wind turbine blade.The main research contents of this paper are as follows:(1)The material properties of SMA wire at different temperatures were studied and the energy dissipation and loss factor of single ring were calculated by simulating the stretching cycle of memory alloy wire at different temperatures.The accuracy of ANSYS simulation of SMA is proved by comparing with the experimental results made by others.By simulating the stretching cycle of SMA thin plate,the influence of different temperature and strain amplitude on the stress-strain curve of SMA was studied.The influence of different temperature on the vibration suppression effect of SMA was studied by pasting the damping layer on the upper surface of composite cantilever beam under harmonic pressure.(2)Wind turbine blades composite material cantilever beam is simplified to a pair of closed room,the SMA as damping layer paste in different locations of the cantilever beam,by harmonic pressure and pulse load,the different position of SMA to double room closed cantilever vibration suppression effect of the free end displacement response,at the same time shows the SMA finiteness of the impact of structural stiffness.In addition,the influence of the content of SMA and the thickness of SMA damping layer on brake suppression under pulse load was studied.(3)Using the material design module in Workbench,the elastic constant and density of hybrid composite monolayer plate in SMA layer are calculated.When the content of SMA is the same and the total thickness of the composite is the same,the stress and strain curves of the interlayer SMA hybrid composite and the interlayer SMA hybrid composite are the same in the tension and compression cycle test.The phase transformation constants of the hybrid composites in SMA layer were calculated.The direction of SMA is consistent with that of matrix fiber.(4)The damping effect of SMA laying position on displacement response of wind turbine blade under harmonic pressure is studied.The influence of SMA laying Angle on vibration suppression of blade and the influence of SMA composite material thickness on vibration suppression of blade are studied.In addition,the harmonic response of wind turbine blade is analyzed by comparing the influence of SMA laying position on vibration suppression. |
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