Research On The Mechanical Performance Of Cross-plate Type Steel Tubular Scaffold's Joint

Scaffold is an indispensable tool in the construction process.The bearing capacity of the scaffold is directly related to the safety of the project.The commonly used type of scaffold is consist of Fastener scaffold,cuplock scaffold,disk-type scaffold and door type scaffold etc.With the growing maturity of the construction industry,there is a higher requirement for the strength of the scaffold.At present,the development and research of new high strength scaffold have gradually become a trend.The cross-plate scaffold is a new type of scaffold,the main components are the vertical bar,the cross bar,the bolt and the cross-plate.The scaffold has a cruciform plate,this plate connect the horizontal rods by the bolt,the horizontal bar and the inclined rod are connected by the another bolt.The bolt has the function of self locking and provides reliable transmission of force.This paper aims at the unsolved problem of the influence of the wedge tightness of the bolt on the rotational stiffness of the cross-plate scaffold.64 groups of bending stiffness test of nodal tangent were carried out in order to accuire the the influence of the wedge tightness of the bolt on the rotational stiffness of the joint of the cross-plate scaffold,it's found that the bending stiffness changes with increasing depth of wedge bolt.Several tests were carried out with the reference to the Chinese scaffold specification,including vertical bending strength test and transverse bending strength test,tensile strength test of crossbar joints,pullout resistance test of bolt and bending shear test of cross-plate.The vertical and transverse flexural strength of the node as well as the M-? curves were obtained through the test,the formula of M-? curves were fitted.The damage forms of the components in several tests were analyzed,the pullout resistance of the bolt,the ultimate tensile force of the cross-plate and the ultimate bearing capacity of the bending shear of the cross-plate were obtained.The entity models of node components were established with the ANSYS software,the simulation calculation of the bending stiffness,bending strength and pullout resistance of the joints was carried out,the conclusions obtained and the conclusions obtained from the experiments were mutually corroborated.Stress concentration in cross-plate was found in simulation calculation,in order to solve this problem,modified models were established and calculated,it's proved that stress concentration didn't exist in modified models.The cross-plate scaffold models were established,the stability bearing capacity of the frame is calculated and compared with the test results of the frame,the validity of models were proved.Then we analyzed the influence of several factors on the bearing capacity of the frame,such as the wedge tightness of the bolt and flexural rigidity in three directions,it lays the foundation for more in-depth study of the bearing capacity of the cross-plate scaffold in the future.