Study On Hysteretic Behavior Of An Assembled Joint With Opening In Replaceable Beam Web

There is less research of weakened joints in steel frames on how to achieve the assembly and quick replacement.An assembled joint with opening in replaceable beam web is proposed in this article.The finite element method is used to study the mechanical properties under monotonic loads and the hysteretic behavior under cyclic loads of the new joint,and design suggestions are proposed.The finite element software ABAQUS is used to carry out finite element modeling and analysis on the weakened joint with opening in the beam web and the end-plate beam-to-column connection.The experimental results and finite element numerical simulation results are compared to verify the correctness and reliability of the finite element modeling.The mechanical properties of the new joint and the traditional end-plate joint are compared and analyzed.The results show that the ultimate displacement of the new joint is improved greatly under the condition that the bearing capacity is reduced less compared with the traditional end-plate connection under the condition of monotonic loads,and it shows good mechanical performance.The plastic hinge of this new joint appears at the weakened part of the replaceable beam web under cyclic loads,which inhibits the development of plastic deformation at the end-plate welds,reduces the stress on the end-plate welds,end plates and high strength bolts.The end plates and beams and columns on both sides are well protected.the purpose of quick replacement after the earthquake is achieved.while brittle damage is avoided.The radius of the opening in the beam web,the distance from the center to the end plate at the beam end,the distance from the center to the end plate at the beam connection,axial compression ratio of the column,the thickness of the end plate at the beam end and the thickness of the end plate at the beam connection are used as different changing parameters to study the influence on the hysteretic performance of the new joint by applying cyclic loading to the model.In order to make the plastic hinge appear at the weakened part of the replaceable beam web and improve the force performance of the joint,it is recommended that the radius of the opening in the beam web r can be set to（0.225～0.25）h,and the distance from the center to the end plate of the beam l₁ can be set to（0.7～0.8）h,and the distance from the center to the end plate at the beam connection l₂ can be set to（0.7～0.8）h,and axial compression ratio of the column can be set not more than 0.6,and the thickness of the end plate at the beam t₁ end can be set to（1.33～1.56）t,and the thickness of the end plate at the beam connection t₂ can be set the same as t₁ or appropriately reduced,but it should not be less than the diameter of the connecting bolts,where h and t are the beam section height and the column flange thickness respectively.