Analysis Of Second-order Effect In The Rigid And Semi-Rigid Steel Frameworks

In conventional steel frame analysis,the behavior of beam-to-column connections is treated as either pinned or rigid joints entirely. Pinned joints means no moment could be transferred from beam to column,so rotations of beams and columns are independent each other;Although,rigid joints means included angle between beam and column holds the line,from unchanged frame without loads to transfigured frame with loads. These idealized assumptions predigest the analysis and design of steel frame consumedly,but they could induce insecurity or conservative design,because in practice engineering,to a certain extent,so-called pinned joints possess rigidity,and so-called rigid joints possess flexibility.hi this paper,we consider the precise analysis of connections could be gained by the concept of semi-rigid,due to the development of computer. At the same time,the geometric nonlinear analysis is an important component in the ultimate design of steel frame. In this paper,we analyzed effects induced by the geometric nonlinear on the rigid steel-frame and the semi-rigid steel-frame,by use of the theory of beam-column and the theory of big-displacement & small-transfiguration. We also discussed the difference between the rigid steel-frame and semi-rigid steel-frame.