Modeling Of Steel Truss And Study On The Mechanical Roperties Of Beam-column Joint Based On Full-scale Experiment

Among steel buildings, the steel truss, a normal structure, is widely used in industrial buildings, storages, airport terminals, terminal markets and so on. Scholars from home and abroad have accumulated large amounts of experience in research and structure design. Sometimes, in order to simplify the calculation, the joint of the calculation models often use ideal joint or rigid connection, and the loads are only on the joints. However, among the steel roofs, the sections, joint model and other factors all affect the reactions of the structure. For example, in fabricated steel roofs, the joints are bolts connections, among which the actual forces, hole elongations, hole slip and other factors make the rigid of the joint between ideal joint and rigid. Besides, the truss members have axial force, bending moments and shear forces, under the node loads. The differences between Calculation model and the actual structure of the production will affect the internal force distribution and the overall deformation. As a result, it is important to research on the calculation models and properties of the joints.This paper is based on the actual project of converter station valve hall, which is a trapezoidal steel roof truss and spans 42 meters. All the joints are high strength bolts. To avoid the scale effect and consider the situations of joints, we conduct a full-scale experiment. Based on the full-scale experiment, we analyze the calculation models of the roof and properties of the beam-column joint.The instruction of this paper describes the selection of the experimental model, monitoring point arrangements and loading scheme. It analyzes the deformations and internal force distributions under the designed loads. Then it summarizes the laws of the second moments. The data from full-scale experiment are bases of analysis of calculation models and beam-column joints in the following articles.Considering the number and size of the bolts, the sections of the members and the sizes of the joints panels, it spends a high price to analyze every single bolt. As a result, to simplify the calculation, the paper first analyzes the three models from Frater and Packer:hinged joint (P), rigid joint(R), rigid hinged joint (PR). To consider the effect of the beam-column joint in the lower chord, the paper recommends model RS based on the rigid model R:the spring element is equivalent of the semi-rigid joint. Afterwards, to sharp the accuracy of the calculation, the paper recommends rigid zone plus spring model to consider the effect of the rigid zone.Based on the full-scale experiment, the research of the beam-column joint summarizes the normal stress and shear stress distribution in the beam-column node areas, conducts the finite element model of the node, whose loads on the FEM are from the conversions of experiment strains, and compares the FEM data with the experimental results. The rotational stiffness calculated from the FEM could be used in the calculation models.