Analysis On Stability Of The Steel Tubular Bracket Based On The Mechanical Properties Research Of Cuplock Nodes

With the development of modern civil engineering industry, steel tubular bracket with bowl-button-type connection because of the reasonable structure, easy fabrication, flexible operation, high bearing capacity, strong adaptability and some other reasons has been widely used in the construction. But steel tubular bracket with bowl-button-type connection buckling collapse accidents happened frequently, it’s due to the insufficient recognition of the system,incomplete theory and the shortage of construction management and so on. Therefore, the study on the safety of scaffold system has important significance for improving the stable bearing capacity and avoiding the buckling collapse accidents.First, this paper introduced the structural stability theory and the theory of finite element buckling analysis, and simulate cuplock nodes by spring element of ANSYS based on the theory of semi-rigid nodes, and then set up the steel tubular bracket model.Second, the article carried out the research of the overall buckling of steel tubular bracket with different connection mode, and reached some main conclusions: the steel tubular bracket with semi-rigid connection was more realistic, and the stable bearing capacity increased with the increase of tightening torque. By analyzing the stress state of cuplock nodes while the steel tubular bracket was buckling, the paper pointed out that the overall structure usually damaged prior to the cuplock nodes.Thirdly, the author analyzed the local buckling of steel tubular bracket with or without the wood, and drew some conclusions: the local buckling changed the order of poling instability and reduced the stable bearing capacity of structure, but the wood could increase the stable bearing capacity.Then, the author completed the analysis of the factors effecting the the stable bearing capacity of steel tubular bracket, and put forward some reasonable suggestions of the erection.Finally, based on a continuous box girder bridge with uniform section, this paper analyzed the overall stability of steel tubular bracket, calculated its’ bearing capacity while some upright tubes were unevenly stressing or differential settlement in the process of pouring concrete, and got some conclusions:semi-rigid connection was more realistic, the stable bearing capacity was bigger while concreting from midspan to two terminals,and upright tubes’ differential settlement would reduce the stable bearing capacity.