| With the large-scale construction of high-voltage transmission lines,the aeolian vibration of transmission lines has become an international concern.Although this type of vibration has a low amplitude,the vibration lasts for a long time and is in a high-frequency state,which easily causes fatigue damage to the transmission line,thereby affecting the reliability of the transmission line structure.Therefore,in order to reduce the damage caused by the damage of the transmission line,it is of great significance to study the aeolian vibration response and mechanism of the transmission line under the wind environment of the atmospheric boundary layer.The CDRFG method based on the Fourier synthesis method is used to simulate the turbulence inlet of the atmospheric boundary layer,the air wind field model is used to verify the consistency of the target position and the turbulence characteristics of the target input,and the method of increasing the inlet turbulence in proportion is adopted to solve the turbulence The problem of attenuation.Numerical simulation of the flow field around a fixed wire when the Reynolds number is 3900,and comparing the simulation results with previous experimental results,verifies the rationality of the three-dimensional segmental wire model and related calculation settings in this paper.Numerical simulation of the fixed circumfluence and aeolian vibration of transmission lines under the wind field of the atmospheric boundary layer.By simulating the flow around a fixed wire under the subcritical Reynolds number of4080,the aerodynamic parameters of the wire wall and the characteristics of the surrounding flow field under different turbulence of the incoming flow are analyzed.Further establish the cross-wind aeroelastic numerical model of the segmental wire,and calculate the dynamic response of the wire under various incoming flow conditions based on the Newmark-β method,and focus on the study of the wire displacement amplitude and frequency lock range with the incoming flow wind speed under each incoming flow turbulence.The mechanism of the aeolian vibration of the transmission line was studied.The wind energy input power of the wire is calculated by using the velocity and lift time history of the wire aeolian vibration obtained by the CFD numerical simulation,and the self-limiting mechanism of the aeolian vibration is analyzed through the relationship between the wire wind energy input power and the amplitude ratio.Taking the CFD numerical simulation of the displacement time history of the conductor aeolian vibration as input,combining the empirical mode decomposition method(EMD),random decrement method(RDT)and Morlet continuous wavelet to identify the aerodynamic damping ratio of the transmission conductor,and analyze the incoming wind speed,The influence of incoming turbulence and aeolian vibration displacement factors on aerodynamic damping ratio.The dynamic bending strain value is calculated based on the CFD numerical simulation of the aeolian vibration dynamic response of the wire.It is judged whether the dynamic bending strain value under the flow conditions in this paper meets the safety standard of aluminum stranded wire,and the aeolian vibration response obtained by the numerical simulation and the energy balance method is carried out.Compared.Then,according to the statistical information of Shenzhen’s perennial climate,the joint probability distribution of wind speed and wind direction was obtained to calculate the most unfavorable erection direction of the conductor.The aeolian vibration damage rate of the conductor was calculated by the dynamic bending strain value combined with the Miner cumulative damage principle and the Wohler curve to obtain the fatigue life.Further study the influence of various factors on fatigue life,including erection direction,incoming turbulence,whether to consider the static stress between strands,and finally measure whether the aeolian vibration of the conductor meets the safety design standard. |
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