The Mechanism Research On Formation About Plastic Hinge Of Steel Frame Structure Based On Ductility Node Analysis

With the gradually development of high-rise and large buildings, the steel structure is gradually favored for its light weight and high strength characteristic. While the connection of node about the steel structure is the weakest link under seismic load, before the steel play the characteristics of light weight and high strength, the structure already damage. Therefore we need to strengthen the strength of the connection in the steel structure with the purpose to improve the ductility performance of nodes, there has been a lot of domestic and foreign scholars developed the different node types on ductility for this problem, But if you need choose a suitable weaken type and gives the corresponding design method, you should to research the essence of plastic hinge outward.The paper begin with summarizing the definition and evaluation indexes about ductility performance, and then give the theoretical calculation formula of ductility coefficient about different section type of corresponding through the theoretical derivation. Then this paper discusses the concept and evaluation index of energy dissipation capacity based on hysteresis curve analysis.Based on the predecessors on research about ductility node, this paper choose the type of weakening node with web hole, carried on the theoretical derivation about the difference between the traditional steel frame structure model and weaken the steel frame structure model with the increment variable stiffness method. Through theoretical derivation, It is concluded that the different structure of the ultimate bearing capacity is different, and the difference between the corresponding failure mode, and then we got the real reason for plastic hinge outward about ductility node.Then, through the test to verify the accuracy of the theoretical derivation, at last we got the same conclusions with the theoretical derivation. At the same time, during the test scheme design period we had taken the related research on the test device about out-of-plane instability in frame structure, and finally successfully solve the problem of out-of-plane instability.Finally, this article through the comparison between results of experiment and finite element to ensure the accuracy of the finite element calculation, and then explore the ductility and hysteretic performance and energy dissipation capacity about the steel frame structure model with weaken and the traditional steel frame structure model with finite element method. The related research results of this paper provide a good foundation for the design and promote use of the ductility node type in steel frame structure.