Simulation Analysis Of Hysteretic Behavior Of Joints Of Prefabricated Reinforced I-Beams And Steel-Pillar-Columns

At present,the country is vigorously promoting prefabricated buildings and using prefabricated buildings as an important way to achieve industrialization of buildings.The assembly-type inclined support steel frame structure developed by the Changsha Grand Group can realize rapid assembly and is one of the forms of industrialized construction of houses,because its main board(combination of truss beam and floor panel)is assembled with diagonal braces in blocks,the assumption that the floor panel is infinitely rigid in its plane cannot be fully satisfied.Therefore,this paper proposes to change the truss beam to common I-shaped steel beam,the beam is made of laminated cast-in-situ concrete panel to meet the assumption that the panel is infinitely rigid in its plane,and the height of the structure can also be reduced,so it~’s scope of application is wider.In order to discuss the seismic performance of the fabricated inclined support beam-column connection node,this article used the nonlinear finite element program ABAQUS to establish the model of the connection joints of fabricated inclined support beams and columns.Considering the factors such as material nonlinearity and geometric nonlinearity,this article researched the hysteretic behaviors of the joints under low cyclic loading.The rationality of the finite element model was verified by the same kind experimental data.On this basis,this article analyzed the influence of the parameter change on the hysteresis behaviors of the fabricated inclined support beam-column connection node.Finally,the influence of the change of the beam-pillar line-stiffness ratio,and the angle of diagonal support and the beam on the hysteretic behavior of the joint were obtained.The research content and achievements are as follows:(1)The new type of prefabricated inclined support beam-column connection node has good ductility and energy dissipation capacity.And it has strong resistance to horizontal load.The plastic deformation of the structure appears on I-beams and inclined supports.This node form meets the design requirements of"strong column and weak beam",As a support member,the diagonal support plays a key role in resisting load and deformation;(2)The angle between the diagonal support and the steel frame beam is an important influencing factor to the initial stiffness of the joint between the beam and the column.With the increase of the angle between the diagonal support and the steel frame beam,the initial stiffness of the beam-column node decreases.The maximum bearing capacity of the structure also decreases.(3)When the angle between the diagonal support and the steel frame beam are45~?and60~?,the hysteresis curve of the test piece is full and stable under the low-cycle reciprocating load.The hysteresis loop hasn’t obvious rheostriction,and there is no abrupt change in the joint stiffness and bearing capacity.This node form has good energy dissipation capacity and ductility performance,and the"plastic hinge"appears on the steel frame beam outside the node domain,meeting the design requirements of"strong nodes and weak components";(4)The stiffness ratio of the beam-column line is an important factor on influencing the initial stiffness of the joints of the beam-column.With the increase of the stiffness ratio of the beam-column line,the initial stiffness of the beam-column joints increases and the maximum bearing capacity of the structure also increases.However,the stiffness ratio of beam-column line shouldn’t be too large and it should be controlled below 0.6 generally.Otherwise it is easy to cause diagonal support to yield before the steel frame beam.