Hysteretic Behaviour Of Square Hollow Section(SHS) Brace-H-shaped Chord T-joints Loaded By In-plane Bending

Due to its superior mechanical and practical properties,like the high lateral ragidity,the strong bending resistance ability and the huge convenience of construction,H-shaped steel is widely used in many public and industrial architectures in recent years.Compared with the traditional steel tube,H-shaped steel is much more suitable for architectures with huge load and span.Also,seismic fortification has become an important factor of architectural structure design.To achieve the goal of seismic fortification,the building structure should have good ductility and energy dissipation capacity.According to the earthquake damage investigation,it can be seen that many buildings collapse due to the destruction of joints.So as an important indicator to measure the energy dissipation capacity of the structure,it is of great significance to investigate the hysteretic behavior of joints.In order to study the hysteretic behavior of reinforced joints,experimental research and finite element(FE)analysis on the non-reinforced and transverse stiffener reinforced square hollow section brace-H-shaped steel chord T-joints were conducted.Firstly,two specimens with different brace height were fabricated for experiment investigating.The first specimen consists of three non-reinforced samples with changing width of branch section.And the second specimen contains three transverse stiffener reinforced square hollow section braceH-shaped steel chord T-joints.The test phenomena and failure mode of the six samples under axial cyclic loads at the ends of the branch were observed respectively.And the hysteretic behaviors of the joints were evaluated according to the hysteretic curves,skeleton curves,ductility coefficients and energy dissipations.The results revealed that this kind of joint has a good hysteretic behavior.The wider the branch section,the better the hysteretic performance of the joints.At the same time,compared with the the specimen without reinforced sample,the specimen with reinforced sample possesses fuller hysteretic curve,and it can improve the hysteretic behavior of joints more effectively.Then,the FE models of the six transverse stiffener reinforced square hollow section brace-H-shaped steel chord T-joints were built in FE software ABAQUS.And the models were validated by the experimental data obtained from the cyclic loading test.Comparing the results of the hysteretic curves,skeleton curves,energy dissipations,stress distributions and failure mode of the FE analysis and the experiment,it showed that the results of the FE analysis and the test were in good agreement.So the FE models were validated successfully.Finally,based on the verified FE models,a parametric study was conducted to investigate the hysteretic influences of ?,2?,?,? and n on hollow section brace-H-shaped steel chord T-joints.And the recommendations of the ranges of the geometric parameters were given for the joints design.