Research On Static Behavior Of Stepped T-type Rhs Joints With Chord Plate Reinforcement

Hollow Section Structures (HSS) are widely applied for their advantages such asgraceful appearance, excellent structural property and great economic performance. ForHSS, when the load-carrying capacity of individual joints can’t satisfy design demands,it is obvious that using reinforced joints is an effective and economic way. At present,there’s no design formulas for reinforced RHS joints in design code of steel structures inour country. Based on the research results of reinforced joints obtained in our countryand other countries in recent years, this paper studied the static properties of T-typeRHS joints reinforced with plate on the flange of chord, which would be meaningful forthe revision of our country code. Specific details are as follows:Firstly, in the finite element (FE) model of the reinforced RHS joint constructed byANSYS, SOLID95elements, TARGE170and CONTA174contact elements wereadopted. Meanwhile, the effect of boundary conditions, fillet and welds were included.Compared with the experiment results of others, the accuracy of the FE model wasverified. According to the simulation result, the ultimate strength and failure mode ofthe reinforced RHS joint were got.Secondly, plenty of parameter analysis of joints reinforced with plate on the flangeof chord with no chord axial load has been conducted, mainly to investigate theinfluence of geometrical parameters on failure mode, joints’ efficiency and ultimatestrength. These geometrical parameters included ratio of the thickness of stiffening plateto the thickness of chord member tc/t0, ratio of the length of stiffening plate to the heightof web member lc/h1, ratio of the width of web member to the width of chord member β,ratio of the width of chord member to the thickness of chord member γ, ratio of thethickness of web member to the thickness of chord member τ and ratio of the height ofweb member to the width of chord member η. Based on the result of parameter analysis,the accurate ultimate strength computational formulas were obtained through themulti-parameter regressive analysis. Besides, through improving the plastic hinge model,the accurate theoretical formulas for the joint capacity were presented.Finally, plenty of parameter analysis of joints reinforced with plate on the flange ofchord with chord axial load has been conducted. Based on the ultimate strengthformulas of no chord axial load, the correction factor which reflected the influence of chord axial load was obtained. By which the ultimate strength of the joints with chordaxial load can be calculated.