Experimental Analysis on the Mechanical Properties of Joints in Disc⁃Button Steel Tubular Scaffolding Under Different Wedge Tightness Conditions

In order to explore the influence of the degree of plug wedge tightness on the torsional stiffness of disc-button steel tubular scaffolding， the mechanical properties of the steel tubular scaffolding joint were reasonably analyzed. By constructing the specimens of ϕ48 and ϕ60 connection joints of disc fastener frame， the torsional stiffness tests of the joints under different wedge tightness conditions were carried out， and the influence mechanism of plug wedge tightness on the torsional stiffness of the disc-button joint was revealed. Through quantitative analysis of the semi-rigidity of the joint， a reasonable range for plug wedge tightness was proposed. Through statistical nonlinear regression analysis， the relations between initial torsional stiffness and plug wedge tightness in disc-button joints were obtained. The analysis results showed that ： the plug wedge tightness had a great influence on the torsional stiffness of the disc-button joint. The plug wedge tightness should be controlled within a reasonable range to meet the bearing capacity requirements， and by using the "semi-rigid-relaxation-slip" trilinear piecewise broken line model， the torsional line stiffness of disc-button joints at different stages within different wedge tightness ranges was obtained， so as to systematically characterize the mechanical properties of disc-button steel tubular scaffolding and avoid security risks that caused by structural defects.