冲击荷载作用下钢管混凝土桁架T形节点破坏模式有限元分析  

Failure modes study on T-joints of concrete-filled steel tubular truss under impact loads

作　　者：李安令 曲慧[1] 黄文金[2] 

机构地区：[1]烟台大学土木工程学院,山东烟台264005 [2]福建农林大学交通与土木工程学院,福建福州350002

出　　处：《建筑结构学报》2013年第S1期134-139,共6页Journal of Building Structures

基　　金：国家青年科学基金项目(51108399);山东省高等学校科技计划项目(J11LE11);山东省自然科学基金联合专项(ZR2011EL046);国家自然科学青年基金项目(51008079)

摘　　要：由于钢管混凝土桁架的主管内填混凝土,一般主管横向刚度远大于支管轴向刚度。当遭受冲击荷载作用时,支管可能提早发生破坏。以钢管混凝土桁架T形节点为研究对象,采用有限元分析,研究了主管直接遭受冲击和通过支管将冲击荷载间接传给主管这两种不同冲击工况下的T形节点的破坏模式。研究结果表明:钢管混凝土土桁架T形节点主管受冲击时,其破坏形式主要表现为钢管混凝土主管受冲击部位钢管出现较轻微的凹陷,相应部位的内置混凝土也出现轻微破碎,支管没有明显变形,但支管和主管交界的焊缝部位应力较大;支管受冲击的钢管混凝土桁架节点,钢管混凝土主管基本没有破坏,但支管随着冲击能量的增大破坏较为严重,直至屈曲破坏;钢管混凝土节点主管或支管受冲击时,随着冲击能的增大,节点的整体变形、局部变形均增大;主管受冲击时,节点局部变形峰值出现在冲击力下降段。Concrete-filled steel tubular truss is composed of chord filled with concrete and brace made of circular hollow steel tube.The stiffness of chord is much larger than that of chord.The brace may become the main member to dissipate energy,and fail before chord under impact loading.In this paper,FEA method is used to analyze the failure mode of T-joint of concrete-filled steel tubular truss impacted on the chord or on the free end of brace.The result shows that: for the joint impacted on the chord,small dent shows up on the zone suffering from impacting,and concrete filled in the tube crashes,the brace barely deforms,and the stress around intersection weld is larger.For joint impacted on the brace,the chord barely deforms,but the brace deforms seriously.With increasing of impact energy,the local and global deformation increase.For the joint impacted on the chord,the maxium deformation of local deformation occurs at the descending phase of impact force.

关 键 词：钢管混凝土桁架 T形节点 有限元分析 抗冲击 破坏模态 屈曲 

分 类 号：TU398.9[建筑科学—结构工程]