Performance Of Composite Joints Under Combination Of Bending Moment And Tensional Force

After the key column fails, the internal force is redistributed by the catenary action of the joints to prevent the progressive collapse of structures, while the joints are under the state of bending moment combined with tensional force. Composite beams are widely used in high-rise buildings which have the advantages, such as high bearing capacity, reduction of beam height and economics.The beam-to-column joints are seen as composite joints. Until now, the experimental and theoretical studies on composite joints only take into account the effects of bending loads.In this paper, the study is focused on the behavior of composite joints under combination of bending moment and tensional force. The finite element software ABAQUS is applied to study the behavior of composite joints. The main contents are as follows:(1) The common finite element software ABAQUS is adopted to create the three-dimension model. The accuracy of theoretical analysis results are validated by comparing with the experimental results.(2) The rigid composite joints are created and analyzed under the state of combination of bending moment and tensional force. The effects of parameters, such as, moment level, reinforcement ratio, rebar strength, concrete strength, etc., on the behavior of joints are investigated. Based on the analysis results, a formula is proposed, which can be used to calculate the bearing capacity of joints under the state of bending combined with tensional force.(3) The semi-rigid composite flush endplate joint model is created. The influence of stiffeners, steel yield strength, bolt strength, thickness of endplate, position of bolt on the behavior of semi-rigid composite joints is studied. Based on the"component method"introduced in Eurocode 3 and analysis results in this paper, a formula for tension resistance of semi-rigid composite flush endplate joints is presented.