Research on Advanced Analysis Method of Semi-Rigid Steel Frames

Abstract

The advanced analysis method used to analyze semi-rigid steel frames is introduced, and the method could take account of many factors influencing structure mechanical performance. These factors include: initial imperfect mode of structure and members, geometrical nonlinearity (P-∆, P-δ effects), material nonlinearity and semi-rigid connections. The Curved Stability Function (CSF) element is built to take account of initial imperfect state, semi-rigid connections and plastic hinge, and derivatives of the second-order element stiffness matrix to extend the spatial element stiffness matrix. The nonlinearity behavior of semi-rigid connections and plastic hinge are simulated by the spring element. Judgment criteria of plastic hinge and spring stiffness values are determined, as well as of the structure failure. The three semirigid steel frames are directly analyzed by the program named NIDA, and the results of NIDA are comparatively analyzed with test results. It is indicated that the results of NIDA are better compared to the test results, verifying validity and reliability of the advanced analysis method used to analyze semi-rigid steel frames.