Finite Element Analysis On Hysteretic Behavior Of Plate-to-shs Connections

In recent years, the Square Hollow Structure Sections(SHS), with its high economical and structural efficiency, is more and more widely implemented into truss and frame structures as chords and columns, replacing the traditional H-sections and I-sections.This replacement requires a change to traditional jointing method,which means the gusset plate has to be welded to the face of SHS in a direction parallel to the chord instead of welded to the H-sections or I-sections. At present, researches on the seismic behavior of this longitudinal plate-to-SHS connections are rare, and few articles are found either in China or abroad. What's more, this need of further researches is even more urgent considering the following three unstudied conditions in this type of joint:1) chord subject to axial compression; 2) Y-shaped joint where the brace plate and the chord are not perpendicular to each other; 3) a joint under bending moment.Hysteretic behavior of the longitudinal plate-to-SHS connections under axial circle loads was studied by finite element analysis software ANSYS in this paper. Analysis of the hysteretic curves, skeleton curves, the area of hysteretic loop curves and the energy dissipation factor curves were carried out to clarify the seismic energy dissipation ability of the plate-to-SHS connections. Comparison between the T-joint and the Y-joint is also done, making a firm basis of theoretical evidence for the design of this type of joint.A longitudinal branch plate-to-SHS connection tends to cause excessive distortion of the SHS connecting face. Such a connection therefore results in a relatively low design resistance usually controlled by deformation limit state. A"through"branch plate connection that extends through both walls of the SHS member can be used to increase the connections rigidity as two times of a standard longitudinal plate connection to reduce the deformation and increase the design resistance of the connection. In this paper, analysis on the hysteretic behavior of this type of improved plate-to-SHS connection is made and comparison with the traditional longitudinal branch plate-to-SHS connection is performed to demonstrate the hysteretic behavior of the through branch plate connection.At last, the variation regularity of the seismic performance with parameters of the longitudinal plate-to-SHS joints under bending was studied to clarify the seismic energy dissipation ability of the connections. Primary analysis of K-type plate-to- SHS joints is done also.