Study On Wind Induced Response And Wind Vibration Coefficient Of Transmission Tower

With the continuous development of China's economy,the demand for electric energy in all walks of life are increasing.The transmission tower is an important part of our country's power transmission.Therefore,the safety of the structure of the transmission tower should attract people's attention.The collapse of the transmission tower has occurred in recent years and the wind load is the main reason,these will affect the country's economic construction and the people's life order.A large number of scholars have shown that the structure of the transmission tower itself is very complex under wind load,and its analytical solution cannot be obtained at present.Both the damage mechanism and the theoretical design are still immature.Therefore,it is very urgent to study wind vibration of transmission lines,especially transmission towers under wind loads.The field measurement of the wind load of the transmission tower system structure is often difficult to implement.Therefore,the aeroelastic model wind tunnel test method is often used to analyze the wind-induced response of the structure.In this dissertation,the aeroelastic model of scale is considered by considering the cross section of a certain straight tower,and then the wind tunnel test is carried out.The wind-induced response is studied and the results are compared with the time domain analysis.The main contents are as follows:(1)Considering the accuracy of model making and results analysis,the discrete stiffness method was used to make aeroelastic models.The modal parameters of the structure were identified by the static tensile test of the aeroelastic model of the transmission tower,and the natural frequency and inherent damping of the structure were obtained.The wind-induced acceleration of the structure measured by the wind tunnel test using random decrement method(RDT)combined with HHT transformation can identify the total damping of the aeroelastic model,then calculating the aerodynamic damping of the model of transmission tower.Studying the aerodynamic damping's changing with wind speed and the angle of change in each wind direction.(2)Wind tunnel tests are performed on transmission towers using different wind speeds and different wind direction angles in terrain category B and typhoon.The response of the transmission tower to the along-wind and cross-wind accelerations under the above conditions was analyzed,and the wind coefficient of the structure was calculated.(3)The shape coefficient of the transmission tower structural system was obtained by the high-frequency-force-balance technologies,and compared with the specifications.An ANSYS finite element model was established.An unconditionally stable random fluctuating wind load was generated by the harmonic synthesis method and loaded on the structure.Using transient dynamics solution to perform time domain analysis in order to obtain the acceleration response of the structure and calculate wind vibration coefficient of the structure.By comparing the results of wind tunnel test and ANSYS time domain analysis,we can provide a reference for structural design of transmission towers.