Non-linear Analysis Of Static Behavior Of K-joints In Steel Pipe Truss Structures With Different Section Forms By Finite Element Method

The development of science and technology, steel tubes have been used widely. K-joins form is one of the most common forms of steel truss structure. In accordance with the difference form of steel tube truss structure, K-joins can fall into circular chord and circular braces (C-C), square chord and circular braces (R-C), square chord and square braces (R-R);According to whether the steel pipe lap join, K-joins can often fall into gap K-joins and lap K-joins. According with whether the hidden seam welding Lap K-joins can fall into hidden seam welding lap K-joins or hidden seam no welding lap K-joins. This article made a finite element analysis of steel truss structure K-joins in three kinds of different cross section forms by Using Nonlinear Finite Element. The static performance, failure mode, joint ultimate capacities, Geometric parameters on the ultimate bearing capacity, and Hidden weld the impact on the ultimate bearing capacity in the paper. Mainly carry out the following research.1. The theoretical basis of finite element method and program verification of the finite element analysis resultsComb through the basic theory of nonlinear finite element,the unit was selected establishment of the nonlinear finite element equation and solving method for this research has a clear train of thought, at the same time, combined with international pipe structure of test database joins data, verify the reliability of the finite element analysis method.2. Calibration analysis of finite element analysis modelAccording to the actual engineering situation, designed the node analysis model, selection of SHELL181element in Ansys finite element software, the C-C, C-R, R-R form of steel tube truss K-joins connected finite element analysis model is set up respectively. Loading mode used both head loading way and pipe loading way.3. The failure mode analysis of K-nodes in different connection formMaking a failure mode analysis of tube structure K-nodes in C-C, C-R and R-R connection forms, K-joins is mainly failured by the deformation of main pipe, and with the different parameters of pipe diameter ratio, head diameter, thickness ratio, overlapping rate and the steel tube pipe axial clearance and slenderness ratio, failure mode is also different.4. The parameter analysis of K nodes steel tubular structure in different connection formThe key parameters that affect the K-joins are main branch pipe diameter ratio, head diameter thick ratio, The head thickness ratio,The ratio of the head length and head diameteramaking a parameters analysis of K-joins tube structure in C-C, C-R and R-R connection form in an all-round way.