| Cellular component is steel component holed in web. It is welded staggeredly by H-steel or I-steel cut into two parts along certain line or circular arc. It is also can be drilled on section-steel according to certain requirements. It has been widely used in flexural members of large span on account of its material saved and easily crossed by pipelines.Cellular component's application is expanded to be used in frame beam and frame column. Cellular steel frame has been applied in many high-rise steel structure in Japan and some European countries, at the same time some corresponding design specifications and construction standards been established. In recent years, the cellular component is applied in the door frame structure in China whith has brought good social and economic benefits. However, there are no corresponding design and construction standards. To improve the application of cellular steel frame, key technology of the cellular steel frame structure should be studied in order to provide reference and basis for corresponding design standards and engineering applications.By means of experimental study and finite element analysis, the several behaviors of beam-column connections of cellular steel frame are investigated under cyclic loading in this paper. Strength, hysteretic behavior and ductility of the connections are analyzed, and design recommendation is given.Six connections are tested under low-cyclic reversed loading, including original steel connection and five connections of cellular steel frame. The effect of the parameters such as d (the distance from the center of the first hole on the beam to the inside flange of the column) and e (the distance from the center of the first hole on the column to the flange of the beam) is considered. When outspread ratio K=1.5, the loading process, failure mode, distributing of stress and plastic deformation are analyzed and compared between six connections. Ductility feature and energy dissipation capacity of cellular connections are compared with original steel one. Based on the four types of the tested connections, finite element models are established. Numerical analysis is conducted with the finite element program ABAQUS. The analysis results are compared with the test results. And a parametric research on the behavior influencing factors of cellular connections has been carried out based on the finite element model.According to the test and finite element results, the loading capacity and stiffness increase remarkably with this cellular structural type which is compared with the original steel and it will help to carry out the design idea of"strong connection, weak component"in the seismic design of the frame. Different failure modes and ductile behaviors of six connections are analyzed, and the critical factors that affect the failure modes of the connections are investigated. It is indicated that this structural type can change the plastic hinge to the section weaken on beam which is far away from the connection domain. In this way, possibility of brittle damage of the welding is dramatically reduced, and the plastic hinge which appears in the section weakens on beam and its development can more fully finish the energy dissipation and exert the strength of materials. At last based on connections of the respective characteristics, the scope of openings on the webs of beam-column is put forward, which has been verified by the experimental results and finite element analysis.All the research results described above have laid a foundation for the study of the theory and method on the seismic design of beam-column connections of cellular steel frame. It can also provide a reference for engineering application.
|
PDF Full Text Request