三种构造型式的箱形截面梁与圆管连接节点受弯性能

上海光源工程采用圆钢管相贯而成的单层网壳结构,网壳结构的边界搭接在箱形截面主梁上形成了箱形主梁与圆钢管焊接连接节点。为研究该连接节点的平面外受弯性能,进行了3个不同构造型式的连接节点试件平面外受弯的滞回性能试验,考察了节点的受力性能和破坏模式。结果表明,3种节点破坏模式均为支管(贯通式连接管)根部塑性变形过大或局部屈曲破坏,其平面外受弯的承载力都能满足节点承载力高于构件承载力的要求,都具有良好的抗震性能。有限元软件ABAQUS的非线性分析表明,在接近破坏时,箱形主梁内部加劲部件的塑性化程度以贯通管式连接最为严重;套管式连接节点中槽形塞焊焊缝的作用在于将内力逐渐从构件传递到节点域,使得节点受力性能更加合理。

Hysteretic property of three connections of box-section beam with circular tubes under cyclic bending

The single-layer latticed structure with unstiffened tubular joints is used in the project of Shanghai Synchrotron Radiation Facility.The periphery of the single-layer latticed structure is enhanced by box-section beams,forming a connection of box-section beam with circular tubes(BBCT).This paper examined the behavior of BBCT subjected to moment.Tests on BBCT with three different construction details under cyclic bending were carried out,to study mechanical behaviors and failure patterns of the joints.Failure patterns of the three joints exhibited excessive plastic deformation or local buckling failure at the root of branch tube(or through tube).All joints with different details can develop higher bending capacity than the jointing members if the quality of welds can be guaranteed.The joints have excellent deformability and seismic-resistance.Nonlinear analysis by ABAQUS shows that the plastic deformation of internal stiffener in the joints with through type tube is the severest among three,and the slot weld of sleeve connection transfers internal force from member to joint zone consistent in almost linear gradient providing a smoother mechanical behavior.