装配式双梁多柱节点框架试验和数值模拟

为研究水平静力荷载下不同角件节点传力特点,以某拟建新型装配式组合轻体板结构住宅工程为研究背景,取其两层一跨平面结构体系为试验原型,设计了包括L型、T型、十字型和灌浆L型4种节点的足尺框架模型的水平静力加载试验,对不同节点形式钢框架的工作性能与破坏特征进行研究,并与ABAQUS数值模拟进行对比验证.根据试验和数值模拟结果,得出了不同节点框架的初始刚度和极限荷载,以及不同截面位置上的应变值.结果表明:新型轻体板结构角件节点连接性能良好,钢框架发生梁铰破坏,节点部位完好,满足“强柱弱梁”与“强节点弱构件”的设计要求;T型节点双柱协同性能较好,L型、十字型节点的柱子易发生变形;节点小斜撑提高了钢框架初始刚度的38%,节点灌浆提高了钢框架初始刚度的14%,双梁完全独立工作,多柱不完全独立工作,通过应变分析与理论推导提出了双梁多柱的等效抗弯刚度计算方法,数值模拟与试验吻合较好,验证了结论的正确性.

Experimental study and numerical simulation on assembled frame with double-beam multi-column joints

To investigate the load transferring mechanism of different corner fitting joints under horizontal static load, horizontal static load tests of full-scale frames with four types of corner fitting joints (shaped of L, T, cross, and grouting L) were designed based on the double-layer single span structure of a proposed new assembled composite light-weight slab structure residential project. The working performance and failure characteristics of the steel frames with different joints were studied, and the results were compared with ABAQUS numerical simulations. According to the results of tests and numerical simulations, the initial stiffness and ultimate bearing capacity of the frames, as well as the strain values at different cross sections were obtained. Results show that the corner fitting joints of the new light-weight slab structure worked well, the steel frames broke in the beam hinges, and the joints were intact, which fulfilled the design requirements of "strong column and weak beam" and "strong joint and weak member". The double columns of T shaped joint had a good cooperative performance, and the columns of L and cross shaped joints were prone to deformation. Small diagonal braces and grouting joints increased the initial stiffness of the steel frames by 38% and 14% respectively. The double beams worked independently, and the multiple columns worked incompletely independently. A calculation method for equivalent bending stiffness of double-beam and multi-column was proposed through strain analysis. Numerical simulations agreed well with the tests results, which verified the correctness of the conclusions.