Experimental Research On Torisonal Mechanism About Semi-rigid Of Coupler-style Steel Tubular Formwork Supports

Fastener-style tubular steel scaffold has widely used in building construction, beeause it has a number of advantages, including:simple detail, versatile, applicable to a wide range, high carrying capacity and relatively inexpensive. But the collapse accidents of scaffold structures are occurred frenquently in recent years, and caused serious casualties and economic loss. The major reasons are that deficiency of design philosophy and the comprehensive understanding of the mechanical behavior of eouPler-stylesteel tubular formwork supports has still not be built, which resulted in the improper configurations of those formwork supports failed before. At the same time, the shortage of construction management and stuff quality are still the factors of the collapse accidents. Therefore the investigation on coupler-style steel tubular formwork supports has important theoretic and practice value.This dissertation enumerated a lot of the collapse accidents of scaffold structures in recent years, It was cleared that an important deficiency of current researches is the ignored the semi-rigid node torsion mechanism,which determined the contents of this paper. The specific use of theoretical analysis, experimental and numerical simulation methods of combining.To verify the torsion properties of right-angle fastener, we are studied rectangular fastener in this paper, Cover bolt torque is the main parameters of the test, And consider the fastener manufacturing process, quality of materials, which may cause the performance of discrete fastener elements, to complete a multi-level, high-volume sample test work, and different conditions for a more comprehensive access to the fasteners to semi-rigid torsion mechanism node performance data.Based on the test results, we established the semi-rigid analytical model of coupler connections is established and a simplified design equation is presented. And made a simplified formula of M-θfor engineering practice, then with the test results and other researchers have made a comparative study.To further clear the node fasteners work of semi-rigid torsion of the template mechanism and the degree of influence the overall performance of stent. Then the large general-purpose finite element analysis software ANSYS11.0 was used to do detailed three-dimensional solid finite element models of coupler connections and the whole framework model template support in which considered material non-linearity and contact non-linearity to get the semi-rigid characteristics of coupler connections, i.e.moment-rotation curves of nodes. And in particular to the simulation results of node fastener test results were compared with the study. Based on the above work,we proposed problems which need further study in this area.