Research On The Safety Of Aluminum Alloy Roof Truss Structure Considering The Semi-rigid Of Plate Joints

Aluminum alloy is favored by designers in the space structure design because of its excellent material properties and good mechanics performan.The joints of aluminum alloy structure are various and suffers from complex forces.Node connections are often designed according to articulated or rigid connections,but they belong to the semi-rigid connection in the actual project.Therefore,there is a safety risk in the design of aluminum alloy structure.In this paper,the safety of aluminum alloy roof truss considering the semi-rigid performance of plate joints is researched.Gusset joint is a common form of joints in aluminum alloy structure.Bolt connection is the main connection mode of gusset joints.In this paper,the factors affecting the load-bearing capacity of aluminum alloy single bolted joints,including the thickness,margin,end distance and bolt torque of aluminum alloy plate are analyzed.The failure modes,load-bearing capacity and the slip curve of the joints under the condition of different plate thickness,margin,end distance and bolt torque are obtained by testing the single bolt connection of aluminum alloy plate,and the stiffness curve of the joints of a single bolt of aluminum alloy plate is obtained.The failure mode,the load-bearing capacity and the slip curve of the joints of the two rows of four bolts of aluminum alloy plate were obtained through the test,and the stiffness curves of the four bolts of aluminum alloy plate were obtained.The stiffness curves of eight bolted connections are obtained from the stiffness curves of four bolted connections through the influence of thickness on slip curve.The stiffness curve is inputed by the ANSYS software into the nonlinear spring element,and the semi-rigid aluminum alloy roof truss structure is combined through beam element and the nonlinear spring element.Through the mechanical loading analysis of the deformation and stress condition,and compared with the joint form roof and beam element simulation of the joint form roof truss and beam element simulation,the influence of the semi-rigid on the safety of the aluminum alloy roof structure is researched.The failure modes,load-bearing capacity and the slip curve of a single bolt connection in various working conditions of a single bolt of aluminum alloy plate are obtained through experimental research.The failure modes,load-bearing capacity and the slip curve of the joints are obtained by testing four bolt connections of aluminum alloy plate.Through research on the safety of aluminum alloy roof truss under hinge joints connection,rigid connection and semirigid connection,it is found that the deformation of the aluminum alloy roof structure under the semi-rigid joints is between the hinge connection and the rigid connection,and the deformation is closer to the rigid connection.According to the rigid connection design,the safety has risk,and the hinge design is good for safety even if it is conservative.