Plastic Hinge Analysis of Steel Frame with Semi-rigid Connections

The moment-rotation relation of beam-to-column semi-rigid connections was simulated with a three-parameter mechanical model which was selected from many mechanical models.The calculation formulas of the fixed end moments,the total stiffness matrix equation and the transmission coefficient of beam elements with semi-rigid connections were presented on the basis of the superposition principle under large displacement,small deformation and the principle of virtual work.Based on these theories,we took into account the effects of the connections and the geometric nonlinearity of the members.By the method of finite element analysis,we analyzed in a comparative way the internal forces of the rigid frame and the semi-rigid frame.The results showed that the proposed methods were reliable and helpful for the engineering personnels.