Research On Mechanical Properties At Panel Zone Of Steel Frame Reinforced Connection

At present, the node for strengthening has been done a lot of experiments andresearch in the world, the method is setting a reinforcement plate in steel framebeam-column joint, by the effect of strengthening the slabs beam end flange ofstrengthening plate makes the plastic hinge formate in the end of the reinforcing plateand beam wing edge, to get away from weak area of the beam-column joint withcomplex stress–panel zone, thus protecting the node, the purpose of preventing nodebrittle failure, but for the geometric parameter changing of reinforcing plate on theinfluence of the node domain, there is no detailed research on it. Therefore, in thispaper three kinds of reinforced node has benn done, including axillary plate reinforcednode(SHP), floor reinforced node (SRP), covering plate reinforced node (CPC),searching the influence on the panel zone with the geometry parameters changing ofreinforcing plate respectively.This paper reviews the research progress of the panel zone at home and abroad,18groups of finite element analysis model is established through references of lengthproposal scope for three types strengthening plate node, putting loading simulation onthe18groups of model under low cycle reciprocating respectively load simulation,Analysising the mechanical properties of the panel zone including the change of stressand deformation on panel zone、equivalent stress and shear stress distribution of panelzone、The shear stress-strain hysteresis behavior on panel zone and the node domain ofskeleton curve and energy dissipation capacity after Simulation of18groups of model.Through the comparison and analysis of finite element simulation results, founding thatthe change of reinforcing plate length has great influence on the mechanical propertiesof the node domain.The comparative analysis and Research on finite element simulation results showthat when the length of axillary plate is0.6-0.7times of the beam height, the length ofribs plate is0.6-0.8times of the beam height, the length of cover plate is0.5-0.9timesthe beam height, the plastic hinge appeared in the far away from the node domainposition basically, protecting the panel zone effectively,Reinforcing plate length is short,plastic hinge appears in the end of the reinforcing plate during loading process, becausereinforcing plate is too short, so it is close to the panel zone and influence the stress of panel zone,if the reinforcing plate is too long, the damage occurred in the beam tocolumn junction and cannot make effective offshoring in the plastic hinge,making greatinfluence on the panel zone.Through the study founding that the equivalent stress and shear stress distributionon panel zone of strengthen node is symmetrical ring at the center of the node domainbasic, intermediate larger in the center and gradually decline towards all groud, theshear deformation and stress distribution are basically identical. Increase thereinforcement plate length can effectively improve the shear bearing capacity of panelzone,and has little influence on shear-shear strain hysteresis of panel zone, but reducesenergy dissipation capacity of panel zone.Taken together, when the length of axillaryplate is0.6-0.7times of the beam height, the length of ribs plate is0.6-0.8times of thebeam height, the length of cover plate is0.5-0.9times the beam height., the nodedomain mechanics performance is the best.