Research On Flange Reinforced Plane Zone At Beam-End

The flange reinforced connection studied in this paper is one typical kind of beam section reinforced forms. By welding a reinforced plate at the beam-end, the reinforced plate connection achieves the purpose of moving the plastic hinge far away from the beam and column interface that will improve the mechanical behavior and protect the connection. In this paper two flange reinforced connections is studied—FPC and CPC.This paper reviewed the study history of the flange reinforced connection, and then made out the design process about plane zone based on the American standard FEMA-350 and ours. It also established the finite element models and compared the results. Two finite element analysis models groups (FPC and CPC) total of 20 were founded to respectively detail flange reinforced geometry affect to the connection mechanical behaviors. Line model specimens under low cycle loading under cyclic loading simulation, respectively, after simulation of stress development, failure mode, hysteretic behavior, ductility and energy dissipation capacity and other aspects of geometry change on the flange joint region mechanical properties to do a more comprehensive study. By comparing the results from finite element simulation analysis, we found enhanced and cover flange enhanced node failure modes, ultimate strength, hysteretic behavior, ductility and energy dissipation, etc. have shown good performance.Through studing the change of flange geometry found that plastic hinges and the bearing capacity of beam-column plane zone has a certain stiffness of the relationship; increase the length of the reinforced plate can increase the ultimate bearing capacity of nodes to improve the hysteretic behavior and consumption energy capacity, but will reduce the ductility of the node; short reinforced plate can not be effectively achieved the relocation of the plastic hinge, when a certain stiffness of the bearing capacity of the node domain, the excessive length of the extended flange plate, plastic does not appear hinge displacement, would increase the portion of the plane zone of force and deformation, which is detrimental to the earthquake; increasing the thickNess of the cover to improve the bearing capacity nodes to improve the hysteretic behavior and energy dissipation is not obvious , cover the increase in the thickNess of the node will reduce the ductility; a thin cover for the strengthening of the role of the node is not obvious, the cover is too thick will cause the node to connect the weld height is too large, difficult to guarantee welding quality, it is recommended to take cover thickNess greater than the calculated value should be less than the thickNess of beam flange plate thickNess. As for reinforced plate's length should be under the joint region and strengthening the rigidity of the principle of equal beam limit.