Compilation And Application Of Calculation Program For Space Frames With Semi-rigid Connections

In the design of steel structures,the design of node connection of components is one of the most important links in the whole steel structure design,and its performance will directly affect the safety,durability and applicability of the entire structure.Especially in seismic areas,the seismic performance of nodes has a significant impact on the force and safety of the entire structure.Once the joint breaks down,the strength of the structural members can no longer be effective.In this paper,two finite element models of six-direction semi-rigid rod end-attached six-spring beam elements and node-attached six-spring beam elements are proposed for the structural calculation of general semi-rigid node-connected space frame structures.Both models consist of three parts: a bar element,six springs attached to the ends of the bar or to the nodes.The six springs include three zero-length wire springs and three zero-length rotating springs,which respectively represent axial semi-rigid,shear semi-rigid,rotational semi-rigid,and torsional semi-rigid.For the above two beam element models,the element analysis and the overall space analysis are performed separately,and the element stiffness matrix and the fixed-end force calculation formula of each model are given.With the help of MATLAB,the static analysis program and the free vibration analysis program of the general semi-rigid connection space frame structure are compiled.It can be used for the structural static calculation when the connection is general nonlinear and the structural vibration characteristic calculation when the initial connection stiffness of the node.Comparison with the ETABS calculation results verifies the correctness and rationality of the program.By introducing an engineering example,it is shown that the different stress performance of semi-rigid node connection structure and rigid node connection structure,and optimizing the connection stiffness of semi-rigid node can make the structure stress more reasonable.