【摘要】 进行6个钢管混凝土K形相贯节点极限承载力的试验,试验参数包括支管壁厚和焊接在主管内壁上的栓钉,同时进行2个钢管K形相贯节点的对比试验。试验采用特制的液压千斤顶和连接件对两支管同步加载。试验结果表明,钢管混凝土节点试件的失效模式与支管壁厚有关。支管壁厚较小时的节点失效为受压支管接头局部屈曲,当支管壁厚较大时为主管钢管(沿受拉支管接头四周)扯裂破坏。主管内的混凝土有助于钢管混凝土K形节点避免发生主管塑性失效和支管压力作用下的主管冲剪失效,并可显著提高节点极限承载力和刚度。钢管混凝土K形节点主管内的栓钉没有改变节点失效模式,但有助于主管钢管与管内混凝土的界面传力,从而提高节点极限承载力和刚度。最后,在钢管相贯节点承载力公式的基础上,提出钢管混凝土K形相贯节点极限承载力的计算方法。更多还原

【Abstract】 Test of six specimens of concrete filled steel tubular (CFST) directly-welded K-joint was carried out. Web thickness and stud welded on chord inside surface were chosen as the parameters. Axial forces were equally and synchronously applied to web members in tension and compression using specially designed hydraulic jack and connection equipment. It was shown from the test results that the mode of joint failure was influenced by the wall thickness of the web tube. For specimens with thin-walled web,web in compression would locally buckle near the connection to chord tube,while for specimens with thick-walled web,tear-out failure of chord tube would occur around connection due to the forces of the web in tension. Filled concrete in chord tube could prevent CFST K-joint from plastic failure and punch failure of chord tube under web′s compressed forces,and obviously increase the ultimate bearing capacity and rigidity of the joint. Shear studs inside chord tube would not change the failure mode,but could improve the transition of the internal forces on the interface between chord tube and the concrete filled inside,thus increase the ultimate bearing capacity and rigidity of the joint. A formula was proposed for predicting the ultimate bearing capacity of CFST directly-welded joint.更多还原