Research On Bearing Capacity Of Multi-Plates-reinforced Joint And Inner-And-Outer Flange Joint In Transmission Tower

Joints design as an important part of steel transmission tower design,directly affects the safety of the transmission line.For Multi-plates-reinforced joint and Inner-and-outer flange joint,this paper analyses the stress characteristics of the two types of joints and puts forward the calculation formula of the bearing capacity.For Multi-plates-reinforced joint,20 specimens of different plates are designed.The mechanical property of this type joint is studied by experiment and finite element analysis,and the mechanics model is established according to working mechanism.The experiment has studied the relationship between load and strain,displacement respectively.The yield bearing capacity and failure mode of Multi-plate-reinforced joint are obtained.Compare the results of finite element analysis and experiment,the reliability of the finite element model is validated.According to the finite element analysis,the reduction factor of bearing capacity of Multi-plates-reinforced joint is obtained.The calculation results based on mechanics model are compared with those of experiments and finite element analysis,it shows that simplified calculation formula is reasonable.Inner-and-outer flange joint is a new type joint,and now there are no specifications for the corresponding calculation methods in spite of domestic and overseas.In order to study the stress characteristics of Inner-and-outer flange joint,this paper experiments with 10 specimens of tension-bending composite and pressure-bending composite loadings.Compare the results of finite element analysis and experiment,the reliability of the finite element model is validated.The hysteresis characteristics of Inner-and-outer flange joint under tension-bending composite loading is analyzed by the finite element method,it gets a method of acquiring the hysteretic curve rely on the static results.Based on the mechanical properties of experiment and finite element analysis,a simplified mechanics model of Inner-and-outer flange joint is obtained.According to the mechanics model,a semi-analytic computing method is given of tension-bending composite and pressure-bending composite loadings.