The Research On Effect Of Semi-rigid Of End-plate Connection On Performance Of Portal Frame

As the typical representation of light-weight steel structure, portal frame is being widely adopted in single-story industrial plants and civil architectures. At present, design of portal frame is performed in terms of rigid joint connection hypothesis, and the effects of semi-rigid feature of end-plate connection on performance of portal frame are not considered. Semi-rigid connection effects not only internal force and displacement of structure but also stability and dynamic characteristics. According to these problems, some reasonable suggestions are proposed in present study, but they are not comprehensive when it comes to how to take consideration of the effect of semi-rigid connection on structure performance during process of structural design. Aimed at the point, the characteristics of portal frame are discussed and studied.In this paper, the general oversea and domestic development situation of light-steel structure as well as the virtue and disadvantage of light-steel structure is concluded systematically. The characteristics of structural style, in-plane stability, earthquake-resistant analysis, foundation design are introduced. In process of optimizing the parameters of gabled frame , some common architectural dimension and column-beam shape are selected. When the portal frame is satisfied with the restrict of code to strength, stiffness and stability, least steel weight per unit area is adopted as optimization target. Some primary discrete parameters which affect steel weight are analyzed, and propositional values of the parameters and optimal shapes of portal frames are also brought forward.Semi-rigid feature of end-plate connection of portal frame is studied;the classification of criterion of rigid connection, hinged connection and semi-rigid connection are determined;the form and conformation of column to beam and beam to beam are described;the curve of relation of joint moment and rotation angle, end-plate thickness and forced load-bearing characteristic of bolt are analyzed;some suggestions on improving joint stiffness are recommended.Using finite element method, one-bay portal frame with semi-rigid connections is analyzed. The effect of different rotational stiffness and beam-column linear stiffness on internal force, deformation, stability and period of portal frame is discussed. Some corresponding design suggestions and calculation tables are put forward.Through experimentation compare and engineering application, the paper points out that the effect of semi-rigid feature of end-plate connection on performance of portal frame should be taken into account in structural design to make the design more reasonable and more consistent with the actual condition.