| As an important part of the substation,the lightning rod structure of the structure is directly related to the normal operation of the substation.In recent years,the lightning rod structure of the transformer frame has repeatedly collapsed under the action of strong winds.The reason for its collapse is the insufficient performance of the lightning rod.This article,under the joint funding of the National Natural Science Foundation of China(51808374)and the Shanxi Provincial Science and Technology Activity Selection Funding Project(DC1900000602),based on the collapse of the lightning rod structure of a substation structure in Xinjiang as the engineering background,based on the one-way fluid-solid coupling principle,Using ANSYS Workbench large-scale finite element analysis software to analyze the overall performance of the structure,the main conclusions are as follows:(1)Through the analysis of the overall mechanical performance of the structure,it can be obtained that the maximum displacement of the structure under the action of strong wind is the top of the lightning rod,and the maximum stress is the connection node of the upper and lower ends of the lightning rod structure;the overall stress and displacement of the structure are proportional to the wind speed As the wind direction angle continues to increase,the overall displacement and stress of the structure have three mutations,respectively30 °,105 ° and 150 °,of which 150 ° is the most unfavorable wind direction angle of the structure;the overall displacement and stress valley of the structure appear At the wind direction angles of 45 ° and 135 °;the overall displacement and stress of the structure change obviously near the wind direction angle of 90 °,indicating that the lateral stiffness of the structure perpendicular to the frame direction is less than that of the parallel frame direction.(2)Based on the analysis of the flow field,it can be obtained that the windward surface of the structure corresponds to the wind speed stagnation point,and the corresponding wind pressure is positive and maximum;the leeward surface of the structure is affected by the vortex shedding and generates a certain wind suction,and the corresponding wind pressure is reduced toNegative value,a certain backflow phenomenon occurs and an irregular vortex field is formed;the two sides of the structure are affected by the separation points around the flow,and the wind speed increases by 50%,corresponding to a large wind suction,and the wind pressure is negative and minimum.(3)The comparative analysis using the first-order and second-order analysis methods can be obtained: under the premise that the wind direction is unchanged,the greater the wind speed,the greater the displacement and stress obtained by the second-order analysis than the first-order analysis,and the second-order effect of the structure also increases.Increase;when the wind speed is less than 15 m / s,the second-order analysis is basically consistent with the first-order analysis results;when the wind speed is greater than 15 m / s,the maximum displacement and maximum stress obtained by the second-order analysis are 1.2 to 2.4 times the corresponding results of the first-order analysis;When the wind speed is greater than 35 m / s,the results of the second-order analysis have exceeded the specified limit,and the first-order analysis is in line with the specifications.Therefore,when a similar structure is subjected to strong winds above 35 m / s,it is recommended that the design should consider the second-order overall effect.(4)Discussed the influence of the use of "flexible flange nodes" and "rigid flange nodes" on the overall stress and displacement performance of the connection nodes in the structured lightning rod structure;"rigid flange nodes" can significantly reduce the maximum displacement of the structure And the stress,of which the maximum displacement is reduced by 9.34% ～ 17.41%,the maximum stress is reduced by 35.2% ～ 51.29%;it is recommended that the new construction of the lightning rod structure and the existing lightning rod structure reinforcement design should adopt "rigid flange joints". |
