圆管截面桁梁极限承载力试验研究

进行了上弦杆为钢管混凝土、上下弦杆均为钢管混凝土的桁梁试件和空钢管桁梁试件的对比试验研究。研究结果表明,弦杆钢管内填充混凝土可提高弦杆的抗压、抗弯和径向刚度,改变节点失效模式,提高节点强度和刚度;弦杆为钢管混凝土的桁梁试件与空钢管桁梁试件一样,结构破坏均是因节点失效引起的;由于弦杆管内填充混凝土提高了节点的强度和刚度,不仅受压的上弦杆而且受拉的下弦杆管内填充混凝土,都会提高圆管截面桁梁试件的整体承载力。最后对管节点的承载力和桁梁试件整体承载力进行了讨论。

Experimental research on ultimate load carrying capacity of truss girders made with circular tubes

Experimental research on three truss girders made with steel circular hollow sections(CHS) under static point loading at quarter span from either end is presented in this paper.The first specimen was a CHS truss girder,the second one was a circular hollow section(CHS) truss girder with concrete filled in the upper chord,and the third one was a CHS truss girder with concrete filled in both the upper and the bottom chord members,forming a concrete filled steel tubular(CFST) truss girder.The test results revealed that filling concrete in the chord members could enhance chord member's axial,flexural and radial rigidities,change the failure mode of joints as well as improve joint performance.However,similar to CHS truss girder specimen,CFST truss girder specimen collapsed due to joint failure.Because filled concrete enhanced joints,not only the truss with concrete filled in the upper chord but also that with CFST bottom chord increased the load-carrying capacity.The strength of CHS and CFST joints as well as load-carrying capacity of truss girders was discussed.