空间刚架结构钢-混结合段的力学性能

Mechanical Properties of Steel-Concrete Composite Section in Space Rigid Frame

为了研究某高速铁路空间刚架结构钢-混结合段的力学性能及传力机理,对其进行了1∶2大比例节段模型试验及非线性有限元分析.对试验模型分别进行正常使用极限状态与承载能力极限状态加载,测试主要构件的应力、变形分布及其随加载历程的变化;结合非线性有限元分析,探讨了结合段传力构件之间的荷载分配关系.研究结果表明:钢-混结合段钢结构、混凝土结构及PBL键贯穿钢筋的应力水平较低;钢结构与混凝土之间相对滑移量较小,二者能协同受力;结合段内混凝土、钢板、剪力键等均处于弹性工作阶段,且应力分布均匀,具有较高的安全储备;钢-混结合段能有效传力,承压板和剪力键各自分担50%的荷载,荷载分配较合理.

Abstract： In order to investigate the mechanical properties and load transfer mechanism of steel-concrete composite section in a space rigid frame structure for high-speed railway, a section model test with a scale of 1 to 2 and nonlinear finite element analysis were carried out. The test model was loaded respectively under a serviceability limit state and an ultimate limit state to obtain the distributions and variations of stresses and deformation of main members in loading process. In addition, the relationship of load distribution between load transfer members in the composite section was investigated by a nonlinear finite element analysis. The research results show that the stresses of steel plate, concrete and perforated rebar in a shear connector are on a low level. The relative slip between steel box and concrete is small, and both of them can collaboratively bear force. Besides, concrete, steel plate and shear connectors in the composite section are all in an elastic stage, and their stress distributions are uniform, indicating that the structure has a high safety margin. The steel-concrete composite section can effectively transfer load, and load distribution is reasonable as bearing plate and shear connectors share half of the load respectively.