Stability Analysis And Numerical Study On The Load-Carrying Capacity Of Semi-rigid Steel Frame

At present, the current design specification of steel structures in our countryclearly points that the design of steel structure should carry out national policies oftechnology and economics. That is to say, the technology is advanced, economy isreasonable, the design is safety and applicable and ensure its quality. However, in thetraditional analysis and design of steel frames, the beam column connection is oftenassumed fully rigid or ideal hinge. Although ideal assumption can simplify theprocess of analysis and design, all connections applied in practical projects arebetween fully rigid and ideal hinge. So that the assumption will cause certain errorseven wrong results. Therefore, it is necessary to consider the influence of geometricalnonlinearity and semi-rigid nodes in order to analyze the actual working performanceof steel frames accurately and reasonably.Based on extensive understanding of domestic and foreign experiment, theoriesand numerical research work for semi-rigid nodes and steel frames analysis, the articlewill study the related theoretical an numerical analysis of the stability andload-carrying of semi-rigid steel frames, summarize some useful conclusions, whichhave the role of guidance and reference to the theoretical research and practicalproject of semi-rigid steel frames.This paper will complete the following task:First, summarize the developing history and research status of domestic andforeign semi-rigid steel frames, generalize the basic theories of semi-rigid connectionand nonlinear analysis theory of semi-rigid steel frames, and research the stiffnessmatrix of considering semi-rigid beam element and geometric nonlinear columnelement.Second, through the introduction of the stiffness matrix of semi-rigid beamelement and the geometric stiffness matrix of column element, this paper comprisesthe geometric nonlinear stiffness matrix which connects flexibility and component.Use finite element method to derive a yuan of two algebraic equations of the buckingload of monolayer semi-rigid steel frame and equations of stability of multilayersemi-rigid steel frame. Use the MATLAB language program to calculate the overall instable buckling load of semi-rigid steel frames and obtain the buckling load ofsemi-rigid steel frames. Comparatively analyze the calculation results and the accuratesolutions solved by the column effective length coefficient method. The results showthat the calculated results obtained by the finite element method derived in this paperand column effective length coefficient method are basically consistent.Third, the paper will study the load capacity of semi-rigid steel frames. Derivethe calculation formula of beam-column stiffness ratio influence on internal force anddisplacement of semi-rigid steel frames through using the matrix displacementmethod. Calculate by MATLAB language program, Solve the internal force anddisplacement of semi-rigid steel frames. Comparatively analyze calculation resultsand corresponding fully rigid frame. Furthermore some advises were provided forengineering designFinally, prospect the further study on semi-rigid steel frames in the future.