Abnormity Node Force Performance Analysis Of Large Span Spatial Steel Structure

With the high-speed development of economy and society, large-span structure has been developing very fast. Higher requirements are proposed for the function and form of large-span structures, therefore there emerge many spatial structure of large span, bar type and complex loading conditions. The nodes located in the stress concentrated area of the large-span space structure and plays an important role in transmission path. Once a node fails, the bearing capacity of the bars which near the node will be severely affected and will induce the path change of the bar force and eventually lead to the destruction of the whole structure. Given that, the study of node of large-span spatial structures has important practical significance.On the background of Qingdao North Railway Station, linear and nonlinear analyses were used to research the mechanical performance of the key nodes with the finite element software ABAQUS. Main conclusions are as follows:1. The complex model and parameter settings of the roof node and arch node were established. Choose three spans arch structure from the total structure, the roof and arch foot pedestal node modeling and parameter settings are carried with the software of ABAQUS, providing a reference for similar complex node finite element model.2. The reasonableness of the model and the security of the key nodes under design loads were verified. Through contrasts and analyses of experimental results, reasonableness of the infinite model and parameter settings was verified, providing a reference for similar complex node finite element model. Finite analyses were carried out on two roof nodes and one arch node under design loads, and the security of the key nodes were verified.3. The nonlinear finite element analyses were carried out on the key nodes of the structure and contrast analyses were carried out on the addition of stiffening ribs. Through finite analyses, the ultimate bearing capacity, failure mode and weak section of the key nodes were obtained. Through contrasts between local parts of the nodes with stiffening ribs and those without stiffening ribs, functions of stiffening ribs were specified in improving stiffness and increasing bearing capacity of nodes.