Finite Element Analysis Research On The Hyhysteretic Behavior Of Cover-plate Reinforced Of Box Strengthen-joint Region Connection Of Fringe Frame For Weak Axis Of I-section Column

As a new connection form, box strengthen-joint region of beam-column connection has shown great mechanical properties. In order to further explore its mechanical properties under cyclic loading, the paper carried on the ABAQUS finite element simulation of side frame joints under low cyclic loading.This paper focuses on the standard joint and cover-plate reinforced joint, by varying the parameters of a series of finite element analysis and data processing, and studied the failure mechanism and key member of the nodes, the connection seam stress distribution curve,stiffness classification, stiffness and ductility of matching and other issues, at the same time,this paper also made improvement aiming at the shortcoming of the cover-plate reinforced joint. The conclusions are as follows:1.Standard joint and cover-plate reinforced joint can reach the characteristics of strong domain, and both were semi-rigid connection in sway frames while rigidity connection in lateral frame. Stress beam flange welds connecting along the beam width direction showed a negative V Distribution. Cover-plate can control plastic hinge away from the domin area, and can significantly improve the initial rotational stiffness and bearing capacity of the node. In contrast, the cover-plate reinforced joint stiffness and ductility match better.2.Under high axial compression ratio, the column flange may early buckling, and presented the tendency of "strong beam-weak column", and the seismic performance of joints would be greatly degradation. Axial compression ratio should be controlled within 0.6;3.Compared to height, thickness of skin plate has a more direct and significant impact on the mechanical properties of joint, and should ensure that the minimum thickness of the skin plate to ensure that the joint has matching good stiffness and ductility;4.The length and thickness of cover-plate have obvious impact on the seismic performance of joint, too large or too small would reduce seismic behavior. When the length and thickness of cover-plate were taken at 0.5 times the beam flange section height and thickness, joint has both great stiffness and ductility;5. The larger section of the beam would increase the capacity, and larger section of column would increase the rotational stiffness. In order to ensure the better match of rigidity and ductility, the stiffness ratio of beam to column should be controlled in a certain within reasonable limits;6. With box structure formed by skin plate strengthen greatly, therefore, strong axis bending will not decrease the weak axis connection, the forced properties of weak axis connection still has better seismic performance.7. Beam flange plate connections can significantly reduce the size of the beam flange attachment welds, and can significantly improve the stress concentration at the edges of the weld connection; and in the skin panels plus welding vertical separators can significantly enhance the rigidity of joints, relax requirements of skin thickness, but also to promote the transfer of stress peaks from the edge of the connecting seam to the middle region;Finally, follow-up research content of this article were discussed, and given the content and direction of future research.