Research On Stable Bearing Capacity Of Reinforced Single-angle Leg Member Of Transmission Tower

Transmission tower is the material support of electric power transmission of which continuity is an important feature.In recent years,because of frequent wind and snow disasters,transmission tower designed according to the old code collapsed frequently.A lot of research on the reinforcement methods of transmission tower have been done by many domestic and foreign scholars.But most of these methods need to weaken the section of the original members of the tower.It means that there are certain security risks in the reinforcement construction.Therefore,by using the method of experimental tests and finite element anslysis(FEA),a reinforcement method of the main leg member with the combination of hoop component and reinforcement-assisted angle member is studied,and a parameter analysis is conducted on the bearing capacity of the reinforced specimen.The main contents and results are as follows:Based on the relevant experimental test data,the accuracy of the finite element(FE)model of the unreinforced single-angle leg member is verified and on this basis,two different reinforcement scheme are analyzed.The FEA results indicate that the scheme of which the composite section is approximately biaxially symmetric rectangular section has certain reinforcement effect;At the same time,the reinforcement-assisted member can pass through the transmission tower joint smoothly.Therefore,it is determined as the main reinforcement scheme studied in this paper.Sixteen unreinforced and reinforced specimens were designed and tested.After the test,the failure rule of the specimen is analyzed and summarized,and the reinforcement effect is evaluated.What's more,the value of stable bearing capacity of all specimen is compared with the theoretical calculation results of relevant standard formulas.The test results show that all the specimens have flexural buckling,and the increment proportion of bearing capacity of the reinforced specimens is relatively high.It is found that the ultimate bearing capacity of the experimental test data is greater than the calculated value of the formula.It can be seen that the reinforcement method in this paper has a good application prospect.Based on the experimental test data in this paper,the unreinforced and reinforced FE model is modified.The FEA results show that the reinforced FE model established in this paper can accurately reflect the static mechanical properties of the specimen and can beused for parameter analysis.The parameter analysis results show that the space of hoop components and the leg thickness of reinforcement-assisted angle member have great influence on the ultimate bearing capacity;The yield strength and the type of angle member have great influence on the material utilization proportion(reinforcement coefficient).