Elastic-plastic analysis of steel frame with beam-column semi-rigid connections

A second-order nonlinear analysis was presented for the analysis of a semi-rigid steel frame,which includes the effects of the semi-rigid connections and the geometric nonlinearity of the members.The beam-column element stiffness matrix,which includes the axial forcer and shear displacement effects,and the semi-rigid beam element stiffness matrix were given.The calculation program for the internal force and displacement of steel frame was established.The numerical results demonstrate that the positive moment at the mid-span of beams and column bottom moment are increased and the negative end moment of beams is decreased while the semi-rigid connections and second-order effect in steel frames are taken into consideration.The semi-rigid connections and second-order effect in steel frames influenced the forced performance significantly.