Analysis Of Ultimate Load-bearing Capacity And Full Scale Static Experimental Study Of Multi-plane Welded Joints

As one of the main forms of joints connection in spatial structure,welded joints are widely used for its advantages of beautiful appearance and convenient connection.The security of space structure is mainly embodied in the safety of joints.At present,there is no corresponding method for the design of intersecting joints in domestic and abroad,causes the engineering application to be restricted.Therefore,it is necessary to carry out theoretical and experimental research on the complex intersecting joints.this paper was supported by the Shanxi Natural Science Foundation(2015011062)and the joint training base for graduate students in Shanxi Province(2016JD11),takes the Taiyuan South Railway Station waiting hall roof structure--68# joint as the engineering background,focuses on the multi-plane complex intersecting joint as the research object.The main contents of the research includes the ultimate bearing capacity analysis and full-scale static experimental research of multi-plane welded joints.The main works and conclusions are as follows:(1)taking Taiyuan South Railway Station waiting hall roof structure--68#joint as the research object,a self balanced loading frame was designed for thistest,and carried out a full scale test of static monotonic loading of 2 joints.The stress(strain)variation curve is obtained and the concept of stress concentration coefficient is introduced.The finite element results of stress concentration factor are compared with the experimental results and the results of the finite element simulation are verified.(2)the finite element analysis of the 68# node is carried out by the general finite element software ABAQUS.The failure mode and the ultimate bearing capacity of the 68# joints are obtained,and the ultimate bearing capacity of the analysis is compared with the standard calculation results in domestic and abroad.(3)the influence of the geometric parameters of the joints and the structure of stiffening plate on its ultimate bearing capacity is discussed.The main parameters include the ratio of the branch pipe to the head ?? the angle between the axis of branch and main tube ??the ratio of the branch pipe or the diameter to the head ??the ratio of the head to the head ??the thickness and spacing of the stiffening plate.The results show that the ratio of the branch pipe to the head ??the ratio of the branch pipe or the diameter to the head ??the ratio of the ratio of the head and the ratio of the head ? are more significant to the ultimate bearing capacity of the intersecting joints.the angle between the axis of brace and main tube ?? the thickness and spacing of the stiffening plate have little influence on the ultimate bearing capacity of the intersecting joints.The influence of everyfactor on the ultimate bearing capacity of the joints is as follows: the ratio of the branch pipe or the diameter to the head ?>the ratio of the branch pipe to the head? >the ratio of the ratio of the head and the ratio of the head ?.