栓接装配式钢-混凝土组合梁及其抗剪键的力学性能研究

为了探究摩擦型高强度螺栓在装配式钢-混凝土组合梁中的适用性,采用ABAQUS有限元软件建立了推出试件和简支梁试件的有限元模型。在试验结果验证模拟可靠性的基础上,研究了螺栓预拉力、螺栓孔径、混凝土强度和螺栓强度等因素对单个抗剪键及整体组合梁的影响。分析结果表明：抗剪键的受力过程分为摩擦、滑移、承压和破坏四个阶段；螺栓预拉力、混凝土强度的增大有利于提高摩擦型高强度螺栓的极限承载力和承压抗剪刚度,较大的混凝土孔隙显著降低了螺栓抗剪刚度；提高螺栓预紧力或提高混凝土强度均可增强钢与混凝土部件的组合作用,相反,在抗剪连接程度不变的情况下,提高螺栓等级导致界面刚度分布不均,不利于滑移控制。

Study on the mechanical properties of bolted prefabricated steel-concrete composite beams and the shear connectors

In order to explore the applicability of friction high-strength bolts in prefabricated steel-concrete composite beams, the finite element model of push-out specimen and simply supported beam were established by ABAQUS finite element software. After verifying the reliability of the simulation through experimental results, the effects of bolt pretension, bolt aperture, concrete strength, and bolt strength on individual shear connectors and overall composite beams were studied. The analysis results show that the stress process of shear connector can be divided into four stages: friction, slip, compression, and failure. The increase of bolt pretension and concrete strength was beneficial for improving the ultimate bearing capacity and compressive shear stiffness of friction high-strength bolts, while larger bolt aperture significantly reduced the shear stiffness of bolts. Increasing the bolt pretension or the concrete strength can enhance the composite effect of steel and concrete components. On the contrary, when the shear connection degree remains unchanged, increase of the bolt grade led to uneven distribution of interface stiffness, which is not conducive to slip control.