Collapse Simulation Of Transmission Tower-line System Under Downburst Based On Finite Particle Method

The collapse of transmission tower-line system under downburst involves many structural complex behaviors,including dynamic response,geometric nonlinearity,material nonlinearity,fracture,collide and contact,etc.Compared with the traditional finite element method,the finite particle method has obvious advantages in solving the complex behavior of the structure.Based on the research achievements of domestic and foreign researchers on downburst and its effect on transmission tower-line system,and the finite particle method,using the MATLAB software as an analytical tool,this paper established the transmission tower-line system model and the structural collapse was simulated under downburst.The main research work is as follows:Firstly,the basic concept of the finite particle method was elaborated,the motion equations of the space bar element were established and solved,and the influence of loading time of the slope,the value of the virtual damping factor and updating of the direction angle on the calculation results was discussed.The longer the loading time of the slope and the greater the value of the virtual damping factor could be seen as the structural under static loading,the calculation of the large deformation structural needed to update the direction angle.Secondly,the basic features of the downburst and the numerical simulation method were introduced.The downburst could be expressed by the average component and the pulsating component.The average component could be simulated by the time-varying average wind speed,and the harmonic superposition method was used for the pulsating component.Taking a simple structure as an example,the required downburst was synthesized and the dynamic response of the structure under downburst was obtained based on the finite particle method.Then,based on the finite particle method,the transmission tower model was established,the static analysis and dynamic response of transmission tower were analyzed.Compared with the results of the finite element method,the correctness of the transmission tower model and the self-coding program on MATLAB were verified.On this basis,the transmission tower-line system model was established,and the corresponding downburst was synthesized.The dynamic response of the transmission tower-line system was carried out,and the transmission line made the response of the transmission tower more intense.Lastly,material failure criterion,structural failure mode and the calculation method after failure were defined.The entire collapse process of transmission tower and the transmission tower-line system under downburst was simulated respectively.Compared and analyzed the collapse form and changes of internal force,the influence of the transmission line was further illustrated,and the effects of transmission line on transmission tower could not be ignored.