Research On Circular Tubular K-joints Casing To Strengthen And Bearing Capacity

Circular steel tube connections between nodes in the structure as a whole are an important aspect of the design. Bearing capacity of the joints cannot achieve the overall structure of the node strength. It should be taken to strengthen measures for node failure modes. Members and nodes in the structure design should be considered at the same time, should not be separated from each other, ignored the design may cause the entire structure of the node properties is affected. If under the action of load node cannot reach a stable, altering the rod dimensions may lead to waste, so the nodes were strengthened. In the structure, due to the long-term effects of the load, resulting in fatigue, reduced deformation and bearing capacity, so in order to avoid damage caused by local buckling and therefore to strengthen the node. Structure of the load change means that the change of bearing capacity, for example, the opening operation of the high-speed rail truss bridge joints, load change, the original bridge for testing reinforcement, node carrying capacity plays a key role. On comprehensive social action, are essential when the node is strengthened. And strengthen joints design method in domestic and foreign rarely included in the specification, how to reasonably carry out the intersecting joints strengthening design has extremely important practical meaning for engineering.This paper mainly studies the tubular joint is strengthened, reference in the study of joints in the country some experimental data and theoretical aspects of research results. Tubular joints strengthening methods and their respective characteristics are introduced. This paper principally studies the is in charge of external casing reinforcement. Combined with the selected three groups of K type node, using ANSYS finite element software with finite strain shell Shell181cell function of type K node is established the mechanical model, the numerical analysis model to choose reasonable boundary conditions as well as the division of the precise grid, with elastic plastic large deflection method based on nonlinear element node analysis of strengthening, after K type node and ordinary K type node of the bearing capacity and failure mode of comparison. At the same time of the selected factors namely casing length and thickness in change, to enhance the degree and some mechanical properties change assessment and research. This parameter is the length of the casing and the casing head length ratio l0/L, the thickness of the casing and the director of diameter ratio t0/T. At the same time, a comparative analysis in the casing parameter l0/L,t0/T changes on the K type bushing connection bearing capacity and failure mode effects, comparing the casing the optimum values of the parameters, and to draw some constructive conclusions and should continue to deepen research problems.