INFULENCE OF THE COLLUMN WEB PANEL BEHAVIOUR TO THE CHARACTERISTICS OF BEAM-TO-COLUMN JOINT / KOLONOS SIENELĖS ELGSENOS POVEIKIS SIJOS-KOLONOS MAZGO LENKIAMOSIOS GALIOS IR STANDŽIO RODIKLIAMS
Authors: Urbonas Kęstutis , Daniūnas Alfonsas 
Published: January 2013

The paper reviews the importance of the evaluation of actual Joints’ behavior during the designing and manufacturing of frame constructions. In this paper an overview of methods for evaluation of Joints’ characteristics is presented. The component method, used in Eurocode 3 is introduced in more detail. In addition, a Short overview of beam-to-columns joints’ components is made.

Beam-to-column joint can be split into two components: the web panel and the connection zone. In most cases, the column web panel is a highly significant part that affects joint's characteristics. Internal forces of the joint can deform the column web panel and dismantle it. Therefore, the column web panel can not only affect the initial rotational stiffness of the joint, but also the design moment resistance.

The article presents the results of the three types of joints’ calculations that illustrate the influence of the behavior of the column web panel for the joint characteristics. Calculations were performed with same cross-sections and steel grade of the elements. The difference is that one joint's column web panel was stiffened, while the other one was not.

Welded beam-to-column joint (case 1) with transverse stiffeners becomes more rigid, because after using the stiffeners, no components that could be deformed remain. When the web panel was only stiffened with transverse stiffeners, the design's moment resistance increased by 28%, when diagonal stiffeners were added, design's moment resistance increased by 64%.

If the weakest component of the joint is the column web panel in shear, compression or tension, design resistance of these components can be increased using stiffeners. Then the design moment resistance of the joint increases as well. In the performed calculations (cases 1, 2 and 3), the transverse stiffeners increased the design moment resistance by 28, 30 and 13% respectively, while the use of transverse and diagonal stiffeners together increased the design moment resistance by 64, 67 and 16% respectively.

When components of connection area are sufficiently rigid (case 2; bolts M24; end-plate thickness is 20mm; two rows of bolts are in tension), using column web stiffeners causes the beam-to-column joint to become rigid. In this case, the use of transverse stiffeners increased initial torsional stiffness by 330%. In case 3, when the connection components were relatively rigid (bolt M24; end-plate thickness is 20 mm), using stiffeners the initial rotational stiffness has increased by 153%, but due to its geometry the joint is not stiff enough to satisfy the requirements for a rigid joint with it's behavior. In addition, the transverse and diagonal stiffeners for joints in cases 2 and 3 were no longer increasing the initial rotational stiffness.

When components of connection area are more flexible (cases 2 and 3; Bots are M16 and the end-plate thickness is 10 mm), using stiffeners can increase the initial rotational stiffness of the joint 2–3 times, but the joint won't be stiff enough to be considered rigid.

Santrauka

Straipsnyje apžvelgta tikrosios mazgų elgsenos įvertinimo svarba projektuojant ir gaminant plienines rėmines konstrukcijas, nagrinėjami mazgų rodiklių nustatymo metodai, plačiau pristatytas Eurokode 3 taikomas komponentų metodas ir aptarti sijos-kolonos mazgų komponentai. Ypatingas dėmesys skirtas vienam mazgo komponentui – kolonos sienelei. Tirta kolonos sienelės elgsenos svarba ir poveikis viso mazgo rodikliams. Aptartos įvairios konstrukcinės galimybės kolonos sienelei sustandinti. Pateikti kolonos sienelės poveikį mazgo standžiui ir lenkiamajai galiai iliustruojantys skaičiavimo rezultatai. Skaičiuota nesustandinus kolonos sienelės ir ją sustandinus. Gautieji rezultatai patvirtina lauktą rezultatą, kad sienelė – labai svarbus mazgo komponentas, o nuo jos elgsenos gali priklausyti mazgo sukamasis standis ir laikomoji galia. Kolonos sienelės plokštę sustandinus, visais skaičiuotais atvejais mazgo standis ir lenkiamoji galia padidėjo.