Finite Element Method for Solving Bucking Load of Semi-Rigid Steel Frame

Took two layers of single span lateral sway semi-rigid connecting steel frame to bear vertical load function as the research object, adopting finite element method for solving the bucking load of the whole losing the stability of the semi-rigid connecting steel frame. Using based on the energy method and the three parabolic interpolation deflection curve function to obtain the relationship between the both element ends of internal force and displacement and introducing semi-rigid beam element stiffness matrix and geometric stiffness matrix of element integrate the global stiffness matrix which contains the flexibility of the connections and the component geometry nonlinear, thus deducing the stability characteristic equation of semi-rigid steel frame. And the MATLAB language composition program is applied to calculate the buckling load of overall losing stability of the semi-rigid steel frame, thus obtaining the buckling load of semi-rigid steel frame. The method is a very effective numerical calculating method which can solve the stability problems of relatively complicated stress conditions or relatively complicated structure composition conditions and it can also satisfy the requirement of higher calculation accuracy, easy for programming and calculation and of great practicability.