矩形钢管节点屈服线和冲剪综合破坏模型.doc

矩形钢管节点屈服线和冲剪综合破坏模型 　　摘要：基于屈服线和冲剪破坏模型，对矩形管管节点和板管节点发生这2种破坏模式的支主管宽度比β适用范围进行理论分析，探讨CIDECT规范中给出的支主管宽度比适用范围的合理性，并在此基础上合理考虑沿支管周长刚度变化，对主管可能发生屈服线和冲剪破坏的区域进行分析，给出屈服线和冲剪综合破坏的承载力计算方法。将所得公式的计算结果与试验结果进行对比，并将其与CIDECT规范计算公式进行对比分析。结果表明：该建议公式计算值与试验值吻合较好；β0.85时，CIDECT规范公式低估了节点承载能力，而0.85β1-1/γ（2γ为主管宽厚比）时，CIDECT规范公式高估了节点承载能力。 　　关键词：矩形钢管节点；屈服线模型；冲剪模型；破坏模式；支主管宽度比；适用范围；节点承载力 　　中图分类号：TU392.3文献标志码：A 　　Abstract： Based on the yield line and punching shear model， the application scope of the width ratio β of branch member to chord member was theoretically analyzed when the two failure modes of the rectangular tubetube joint and the platetube joint happened. The rationality of application scope of the width ratio of branch member to chord member proposed in CIDECT specification was discussed. On the basis， reasonably considering the change of stiffness along branch perimeter， the regions where yield line and punching shear probably occurred were studied， and the bearing capacity calculation method of the comprehensive failure model of yield line and punching shear was proposed. The calculated results of the proposed formula were compared with the experimental results and the calculation formula of CIDECT specification. The results show that the calculated results are in good agreement with the test results. When β0.85， the formula of CIDECT underestimates the bearing capacity of joint， and when 0.85β1-1/γ （2γ is the width to thickness ratio of chord member ）， the formula of CIDECT overestimates the bearing capacity of joint. 　　Key words： rectangular steel tube joint； yield line model； punching shear model； failure mode； width ratio of branch member to chord member； application scope； bearing capacity of joint 　　0引言 　　矩形钢管节点主管为矩形钢管，支管为钢管或钢板，主支管采用直接焊接形成节点。由于其加工制作简单、经济性好和造型优美，在桁架桥、拱桥和格构式桥墩中应用广泛[14]。主管对应桁架桥弦杆、拱桥拱肋或桥墩的柱肢，支管则对应桁架桥腹杆、拱桥吊杆与拱肋连接板或桥墩缀杆。作为以上结构最薄弱的环节之一，矩形钢管节点承载力一直是各国学者研究的重点。 　　各国学者对不同类型矩形钢管节点进行了系统的试验研究[512]，结果表明，各类节点主管表面均可能发生塑性破坏或沿支管四周冲剪破坏，并且与支主管宽度比β密切相关。Wardenier等[1315]对矩形钢管节点试验