Nonlinear Analysis Of Multiplanar Tubular Gap KK-joints Made Of Square Chord And Circular Braces Based On Finite Element

Steel circular hollow sections are used extensively in a wide range of structures for their structural efficiency、 aesthetic appeal and relatively low cost. Steel tubes have been gradually studied in countries. However, the most researchers are concentrated on the gapped or overlapped Circular Hollow Section、Square Hollow Section joints. The researchers of multiplanar joints are less,specially KK joints with square chord and circular braces.Thus, a numerical study on the ultimate strength using nonlinear analysis of multiplanar tubular gap KK-joints made of square chord and circular braces is presented.In this paper, the material property, boundary condition, length of member and density of mesh were specified using the typical joints analysis methods by the ANSYS finite element software. The reliability of the finite element model was verified. The research on the nonlinear behavior of directly welded CHS joints was carried out by a large scale of the parameter analysis. The work done is as follows:(1) The aim of the work was to establish a valid and accurate finite element model for an extensive parametric factors to investigate their influence on the joints’ ultimate bearing capacity and failure mode.(2) As there are so many parameters, this paper is going to use the variate controlled method. Three non-dimensional joint geometric parameters (β, γ and τ) and one geometric parameter g are employed in the study. Three specimens in each series were evaluated. So81models using shell element have been built and analysed with ANSYS in total. All chord members are200mm in height and width. All brace-to-chord intersection angle θ are60and brace-to-brace intersection angle Φ are90. All brace members are4.5times brace diameter in length and ratio of twice chord length to chord diameter a are14.Through a systematic comparative analysis, the four parameters all have a significant impact on the strength of the joint.The joint will exhibit a higher joint strength with lower g、higher τ and β. Meanwhile γ value should be better no more than10.The study has given an insight into the many aspects of elastic-plastic finite element analysis in tubular joint technology。...