Finite Element Analysis On Mechanical Behavior Of Beam-column Joint With Beam Flange Openings

Given the researches on the dog-bone connection and beam-column connectionwith reduced web, a new improving connection—beam-column joint with flangeopenings is provided in this paper in order to solve the problem that traditionalwelded-bolted beam-to-column joints often occur failure in the welds at the connectionarea. This modified beam-column connection, boring holes in the beam’s flanges at thejoint area, can move out plastic hinge from the beam ends, meeting the seismicobjective of “strong joint and weak component”, which will protect the joint’s welds inthe earthquake, and make it possible to permit lines across at vertical direction indifferent floors, achieving structure’s beauty.Research contents and corresponding results are including: Firstly, finite elementanalyses on beam-column joint with beam flange openings are carried out undermonotonic load, analyzed influence of openings on the joint’s mechanical behaviors.Both the connection’s load-displacement curve and law of plastic hinge developmentare obtained in analysis, which indicate that openings have little effects on ultimatebearing capacity of the joint, reducing only a certain degree of6%, when openings’ sizeare appropriate. And beam flange openings can meet the requirement of shift-away ofplastic hinge. As a result, this new type joint can reach the target of protecting flangeweld at the connection area.Secondly, parameter analyses are conducted on the relevant factors affected themechanical behavior of the improving beam-column joint with beam flange openings.Analytical results show that the beam-column joint with beam flange openings canaccomplish the goal of plastic hinge’s outward from the beam-column joint zone. Andthe parameters of reduced flange with openings have little effects on the joint’s overall stress property, only having a certain degree influence on the reduced region, in whichthe hole diameter r and numbers of opening n have more significant influence on themechanical behavior of this new joint.At last, related relieving solutions to alleviate stress concentration phenomenonaround the beam flange’s holes induced by opening are given. And correspondingpractical design recommendations are provided and evaluated.