Study On Seismic Behavior Of Top-seat Angle Connections In Partially Encased Concrete Composite Column And Steel Beam

Several earthquake damage showed that rigid joints not only have a poor concentrateddeformation, but also have large residual stress. The rigid joints were easily occur brittle failure.Semi-rigid joints have better ductility, and energy dissipation under earthquake seismic. Thedamage occurred before it has obvious signs. Deformation capacity and energy dissipation arebetter than the rigid one. With the development of high-strength composite structures, the jointof this structure have become research hotspots. Research on semi-rigid composite joint hasimportant valve on engineering application.In order to study the seismic behavior of top-seat angle composite joint connected bypartially encased concrete composite column and steel beam, this paper discussed bearingcapacity, hysteretic behavior, ductility, energy dissipation. And targeted at semi-rigid compositejoints with top-seat angle connections, six groups of specimens were designed. The parameterswere bolt diameter, angle thickness and column flange thickness. Failure mode, the straindistribution of angle, beam, column and the bearing relationship of each member were studied.Through analyzing the seismic behavior indicators of each specimen, the conclusions are asfollowing: The angle thickness was the main failure factor of the composite joints. With theangle thickness increasing, the bearing capacity and rigidity of the joint are magnificentincreased. The maximum increasing amount of bearing capacity was39.8%.The maximumincreasing amount of initial stiffness was51.4%. Bearing capacity degeneration have notapparent undulating，and the ultimate reducing of energy dissipation coefficient was14.8%.Bolt diameter can only improve the seismic performance within a certain range. The incrementof bearing capacity was only6.2%but ductility coefficient was decreased by21.7%.Changingcolumn flange thickness cannot magnificently influence bearing capacity,hysteretic behaviorand rigidity degeneration. Thus, adding angle thickness, controlling bolt diameter, properlyreducing column flange thickness were recommended in seismic design.Modeling and analyzing each specimen by ANSYS finite element software, the result showed that the result of tests and simulation are cooperated well, and have same failure mode.Adding the parameters of angle thickness found out that the ultimate bearing capacity, ultimatemoment and its displacement. Fully studied the relationship between moment of top-seat anglesand load-bearing of each member. Verified initial stiffness formulation and presented compositejoints top-seat angle ultimate moment modified formulation and angle thickness modifiedformulation by using Matlab software. The result recommended an engineering reference forthe future design.