竖向荷载下套管节点装配式交错桁架受力性能研究

Study on the mechanical behavior of assembly steel staggered truss structures with sleeve tube joint under vertical load

为研究竖向荷载下桁架与方钢管混凝土柱套管节点装配式交错桁架的受力性能,按实际受力和等强原则设计了2种不同套管节点形式的1/2比例缩尺交错桁架模型试件,并对其进行了竖向静力加载试验研究,得到了试件的破坏形态、承载力、刚度以及应变分布规律.采用ABAQUS建立了试验试件的有限元模型,以轴压比和混凝土强度为参数,研究了其对交错桁架承载力的影响.结果表明:与按实际受力设计节点的交错桁架结构相比,按等强设计节点的刚度和承载能力都较大,节点宜按等强设计;减小轴压比或提高混凝土强度均会提高结构竖向极限承载力,但差别不大.

In order to study the mechanical behavior of assembly steel staggered truss structures with sleeve tube joint of truss to concrete filled tube column under vertical load, two half scaled specimens were designed, one by the actual internal force, and the other by the full strength. Experiments were conducted to research the failure mode, load beating capacity, stiffness and strain distri- bution of the specimens. The finite element models of test specimens were established by using finite element software ABAQUS, and nonlinear analysis were considered to study the influence of compression ratio of column and the concrete strength in the steel tube to the bearing capacity. Results revealed that the joint designed by full strength had larger elastic stiffness and higher bearing capacity than that designed by actual load, so the joint designed in terms of full strength is recommended. Decreasing the compression ratio of column or increasing the concrete strength in the steel tube can slightly improve the load bearing capacity of the structure.