Analysis Of The Ultimate Strength On Spatial KKK-joints Of Tubular With Large Size

The designing of a Steel Pipe Truss Structure is focus on the design of the joints, especially in the node region of the spatial complex type of tubular joints(KKK-Joints) with large size, both the Geometric characteristics and material properties are very complex, the stress concentrationis serious, affected by many factors, and have Variety of failure modes.It could be found that the analysis of such spatial nodes witch bearing compound forces(at the same time withstand the bending moment and axial force)is also rarely after searching for the existing specifications and information, that made the design and use for tubular joints more difficult. Therefore, a Research for Strength Performance of such nodes has become an urgent problem in the steel pipe structure. This paper has made a systematic analysis of the Ultimate Strength on spatial complex type of tubular joints(KKK-joints) with large size by using the finite element analysis software(ANSYS). Its analysis as follows:1Analyze the parameter changes effect on space KKK type square steel pipe joints Anti-curved ultimate bearing capacity under the different parameters of the β and γ，θ and competent stress, in order to identify the main factors to affect the Anti-curved ultimate bearing capacity, and then through regression techniques to fit such nodes anti-curved ultimate capacity formula under the effect of parameters on joint strength2Analysis the relationship between the flexural rigidity on spatial complex type of tubular joints(KKK-joints) with large size and these parameters by changing the above series of parameters.And then got a regression formula of ultimate axial bearing capacity on such nodes with the previous relationship.3According to the anti-curved ultimate bearing capacity of the node from Chapter III regression analysis as the limits of the additional moment, analysis the node withstand the force of the bending moment and axial force at the same time, and then plotted according to the analysis of the data results in order to got the ultimate bearing capacity formula of the space node at the same time under the action of the bending moment and axial force.4Verify the accuracy and usefulness of the formula derived in the above analysis according the force status by this form of analysis used in the actual project nodes. Provide a theoretical basis for the other projects that might use this class of complex nodes.