The Static Analysis On A Roof Structure Of A Stadium And The Finite Element Analysis About Tubular Joints

Space-truss structures have been widely used in the large-span spacial structuresdue to their good mechanical properties, nice appearance, and relatively low cost. Theresearch on the behavior of joints is a very important part of the design of hollowsection structures, which influent the whole structure. multi-planar tubular KK-typejoints are commonly used in the tubular truss structures, and the stress condition ofthe joints with four web members overlap each other is more complex. With thebackground of steel roof engineering of a stadium, the static analysis of wholestructure and the mechanical behavior of some key joints have been researched,which perhaps will be a reference for the design and research of similar structures.The analysis showed that maximum displacement of the structure, which is56%of the permissible displacement, occurred on the end of the truss, which indicates thatthe stiffness of the structure is large. Maximum structural force appeared on thesupports, according to the result, all the components mainly bear axial force whilebending moment and shear force are small. The stress of the structure meet therequirement after checking. The finite analysis of the joints showed that there aremainly two kinds of failure modes of joints under the ultimate load: plastic failure ofchord members and the yield failure of web members. The joints will probably showplastic failure of chord members when the ratio of axial force of chord members andweb members is large or web members mainly bear axial pressure, and more probablyappear yield failure when the ratio is small or web members mainly bear axial tension.The stress distribution of joint is uneven and the stress concentration is obvious,which is the mainly cause of failure.Internal ring-stiffener was adopted in this paper for the joint that cannot meet therequirement. Fortified joint still in the range of elasticity under design load accordingto finite element analysis and the ultimate load is the1.5times of the design load,which indicates that bearing capacity and stiffness of the fortified joint is provedgreatly, and internal ring-stiffener is an effective strengthening method.