嵌入式波形钢板剪力键推出试验及数值分析

Push-out Test and Numerical Analysis of Embedded Shear Connectors with Corrugated Steel Plates

为探究波形钢板剪力键的抗剪性能和破坏机理,设计了开孔和无孔2类波形钢板剪力键试件,进行推出试验研究。测试了试件的抗剪刚度、抗剪承载力、加载过程及破坏模态,随后采用有限元软件对试验全过程进行模拟,并开展波形钢板剪力键构造参数分析,探讨了混凝土强度、钢板厚度和高度的影响。根据试验和有限元分析结果,提出了波形钢板剪力键承载力计算公式。研究结果表明:波形钢板剪力键具有较高的抗剪承载力和良好的延性,当荷载-滑移曲线进入水平段后,仍能承受较大的相对变形,同时保持承载力不降低。无孔类剪力键依靠倾斜钢板材料的屈服来传递剪力,抗剪承载能力较高;开孔类剪力键主要通过倾斜钢板传递剪力,贯通钢筋和混凝土榫也能发挥一定的抗剪作用。剪力键开孔及设置贯通钢筋能增强混凝土板的整体性,开孔类剪力键试件的裂缝分布范围更大。试件破坏时,波形钢板剪力键发生明显变形,钢材达到极限强度,材料的利用效率高;波形钢板厚度、波形钢板高度和混凝土强度均是影响波形钢板剪力键抗剪承载力的关键因素,设计时需综合考虑并进行合理匹配,以便充分发挥各材料的性能;提出的波形钢板剪力键承载力计算公式与试验测试结果吻合较好。

This paper investigates the shear bearing properties and failure modes of shear connectors with corrugated steel plates by push out tests. The specimens of non-hole and hole-type shear connector with corrugated steel plate were designed, respectively. The stiffness, shear bearing capacity, loading process and failure mode were measured. Finite element models were introduced to check with push out test results and then used to perform a parametric study. The influences of concrete strength, thickness and height of steel plate were discussed. A formula for the bearing capacity of shear connector was proposed according to the experimental and finite element results. Results show that shear connectors with corrugated steel plates has great bearing capacity and ductility. When load reached the bearing capacity, the specimens could still perform a large deformation without decrease of load. The bearing capacity of non-hole shear connector completely depended on the inclined steel plates. For hole-type shear connector, the transverse bars made limited contribution to the bearing capacity. It mainly influenced by the inclined steel plates. The holes and transverse bars could increase the integrity of specimens. The specimens with hole-type shear connectors had larger distribution area of cracks. The material’s ultimate strength of shear connector was reached after failure. Shear connectors performed great deformation and had high efficiency of steel utilization. The thickness, the height of corrugated steel plates and the concrete strength had great influences on the shear bearing capacities. These parameters should be matched rationally to exert their effects sufficiently. The formula proposed matched well with the test results.