加劲肋对钢管相贯节点力学性能的影响

加劲肋可以提高钢管相贯节点的承载力及刚度,进而提高节点可靠性和结构整体稳定性.其中,加劲肋的平面尺寸、厚度、形状以及加劲肋是否贯穿钢管等对节点的刚度、承载力及延性有很大影响.以一个钢管相贯节点足尺试验为基础,通过一系列扩展的有限元模型来分析加劲肋厚与管厚比、加劲肋尺寸与管径比和加劲肋是否贯穿钢管等因素对节点承载力、屈服前后刚度以及延性的影响.研究结果表明,加劲肋可以显著提高节点承载力和刚度.对于仅焊于钢管外的加劲肋,合理的厚度比(加劲肋厚度与管壁厚度之比)为α=0.5 ～1.0;对于贯穿钢管的加劲肋,合理的厚度比为α=0.5 ～0.8；加劲肋边长与管径之比β的合理取值为0.6～1.

Influence of Stiffeners on Mechanical Behavior of Steel Tubular Joints

Strengthening with stiffeners could strongly enhance the stiffness and the ultimate bearing capacity of steel tubular intersecting joints.Accordingly,it will benefit the reliability of the joint and the overall stability of the structure.The factors of the stiffener such as the plane dimensions,shape,thickness and whether or not penetrating the pipe member have considerable impacts on the stiffness,bearing capacity and ductility of joints.In order to investigate the influence of the mentioned factors,a full-scale experiment and a series of finite element modeling were conducted.A few conclusions can be made from the experiment and the FEM results.First,the tubular joints strengthened by stiffeners have higher stiffness and bearing capacity than those without stiffeners.In addition,appropriate magnitude of α for those joints with stiffeners welded on the surface of the tube is 0.5~1.0,while appropriate magnitude of α for those joints with stiffeners penetrating the tube is 0.5~0.8.Finally,the magnitude of β,the ratio of the length of the stiffener and the diameter of the tube,is suggested to be 0.6~1.