Mechanical Performance Analysis Of Steel Frame With Tenon-and-Mortise Joints

With the continuous development of China's economic and technological, the application of steel structure in the construction field is increasingly exensive, nodes'forms of steel frame design have been showing diversity. Steel beam-to-column connections are an integral part of the frames and their behavior greatly affects the overall frame performance. There are many results for the research of the common fastening connections which are composed of deformable parts such as angles, plates, welds, bolts and so on. In this dissertation, a new kind of assembly steel tube frame with the mortise and tenon semi-rigid joint is proposed and discussed the mechanical property of the mortise and tenon joints preliminary. The work was supported by the Natural Science Foundation of Hebei Province, China (Contract No. E2008000438).The mortise and tenon joints are the research object in this dissertation. Numerical analysis modeling of the mortise and tenon joints are studied by using ANSYS finite element analysis software. The simulation results and physical model test results are compared, and the comparison results showing that the finite element model is feasible which is simulated by SHELL181, CONTA173 and TARGE170 elements, and the moment-rotation curves of joints which are in different positions in the framework are obtained. Based on the finite element model of mortise and tenon joints, the portal steel frames with mortise and tenon joints are established. In different working conditions of loading, the moment-rotation curves of joints in the portal frame are gotten. Through comparing of the moment-rotation curves which are obtained in the different loading conditions can be known that the stiffness of joints is changed with the different load combinations. However, the stiffness of joints with assembly steel frame in two directions has different change law. Stiffness of joints with the frame direction of Y is greater than the frame direction of X. In the two framework directions, the mechanical properties of mortise and tenon joints are closing hinge joints when the loading conditions is only the horizontal load. The moment-rotation curves data are obtained which are according to the assembly steel frame within the mortise and tenon joints in the different loading conditions. Many factors are taken into considering such as the characteristic of the moment-rotation curves of the mortise and tenon joints. The fitting formulas of moment-rotation curves are obtained using the non-linear fitting method. Analyzing the variances of the fitting formulas, the index of correlations value R~2 are showing that the fitting formulas are reliable. The researching of assembly steel frame within mortise and tenon joints is just beginning, the dissertation do some preliminary research about the mortise and tenon joints which can provide some reference for the further research about the mechanical properties of the mortise and tenon joints.