Finite Element Modeling And Stability Analysis Of Bowl Button Full Frame Bracket

With the vigorous development of national infrastructure,the use of the full support system has become more frequent.The bowl-type full-frame support system has an absolute advantage in various support systems due to its versatility,high carrying capacity,convenient erection,low cost and no need for other auxiliary equipment.However,due to the irregular design,unreasonable construction and other reasons,the collapse of the bracket frequently occurred.Therefore,in the design of the bowl-type steel tube full-frame system,it is especially important to carry out numerical modeling methods and overall stability studies.Based on the Beijing Chaobai River Bridge as the engineering background,this paper studies the combination of theoretical analysis,numerical modeling and engineering measurement.The main research contents and results are as follows:(1)Based on Beijing Chaobai River Bridge Project,the preliminary design of the bowl-shaped full-frame bracket was introduced,and the selection and arrangement of the brackets and the check calculation of the brackets were introduced.(2)Based on Midas/Civil's finite element modeling of the bowl-type full-frame bracket,the joint connection of the bracket modeling,the connection between the bottom end of the bracket and the foundation,and the connection between the top of the bracket and the square wood were studied.Compared with the actual test results,it is shown that the modeling of the bracket joint should be semi-rigid when the bowl-shaped full-frame bracket is modeled.The connection between the bottom support and the foundation should be hinged,and the connection between the square and the bracket should be half.Rigidity and more are more realistic.(3)Based on the actual engineering background,the factors affecting the stability of the cross-bar arrangement of the bowl-shaped full-frame bracket,the height of the sweeping rod,the length of the top of the pole,the scissor support and the height of the erection are analyzed.The results show that for the crossbar arrangement,In order to consider the safety and economy,when the bracket system is set up with the crossbar,the stability of the structure should be considered comprehensively,and the appropriate spacing should be selected;the height of the sweeping rod should be between 0.3 and 0.4m to maximize the overall stability of the bracket;The length of the rod extending from the top rail is controlled as much as possible to a length of less than 0.3 m.When the length exceeds 0.3 m,the overall stability of the bracket is greatly reduced with the increase of the length;the arrangement of the scissor support is determined by a certain vertical scissors according to the actual situation of the project.The density of the erection is increased and the layout of the transverse scissors is increased appropriately;the height of the erection varies little with the increase of the height,but the effect of the wind load becomes large.