Resistance of gusset-tube DK-joints stiffened by 1/2 annular plates in transmission towers. (August 2019)

• Record Type: Journal Article
• Authors: Li, Fang; Deng, Hong-zhou; Hu, Xiao-yi
• Is Part Of: Journal of constructional steel research. Volume 159(2019)
• Page Start: 560
• Page End: 573
• Publication Date: 2019-08
• Subjects: Gusset-tube connections -- K-joints -- DK-joints -- Annular plates -- Full-scale experiment -- Transmission towers; Steel, Structural -- Periodicals; Building, Iron and steel -- Periodicals; Acier de construction -- Périodiques; Construction métallique -- Périodiques; 624.1821
• DOI: 10.1016/j.jcsr.2019.05.013
• Languages: English
• ISSNs: 0143-974X

Abstract

Abstract: Gusset-tube double K-type joints (DK-joints) stiffened by annular plates are widely applied in transmission towers. However, the literature concerning these joints is scant, as DK-joints are spatial joints, so it is difficult to achieve three-dimensional (3D) loading in experiments. In this paper, full-scale tests of DK-joints were accomplished. An equivalent model in which the brace forces were substituted by a shear force ( P v ) and a bending moment ( M w ) was adopted. Then, the parametric analysis was carried out to derive empirical formulas of the design resistances for DK-joints. Furthermore, the failure patterns and capacities of DK-joints with and without annular plates were compared with those of uniplanar K-joints. The present study obtains that, concerning one gusset plate, the ultimate shear capacity ( P v, u ) of DK-joints is about 0.6 times that of K-joints and that DK-joints stiffened by annular plates have larger ultimate moment capacities ( M w, u ) than those without annular plates. Moreover, annular plates do not affect P v, u but can affect M w, u significantly. Annular plates have a 'hoop effect' on K- and DK-joints. Highlights: Design resistance and failure modes of DK-joints with annular plates were investigated. Full-scale three-dimensional experiments of DK-joints were achieved. Ultimate strength equations for DK-joints with annular plates were proposed. DK-joints with annular plates were compared with that without annular plates and uniplanar K-joints.