Behaviour and design of the ‘lockbolt’ demountable shear connector for sustainable steel-concrete structures
Behaviour and design of the ‘lockbolt’ demountable shear connector for sustainable steel-concrete structures
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DOI：
10.1016/j.istruc.2022.08.062
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发表时间：
2022-10
期刊：
影响因子：
4.1
通讯作者：
Jun-Jun He-Jun;Ahmed S. H. Suwaed;G. Vasdravellis;Sihao Wang
中科院分区：
文献类型：
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作者：
Jun-Jun He-Jun;Ahmed S. H. Suwaed;G. Vasdravellis;Sihao Wang
为了促进钢-混凝土组合结构的可持续发展，需要特殊的剪切连接件，便于拆解。提出了一种锁栓式可拆卸剪切连接器（LB-DSC），其中包括嵌入混凝土板的灌浆钢管，并将其固定在几何兼容的部分螺纹螺栓上，该螺栓固定在组合梁的钢截面的顶部法兰上。以前类似的可拆卸螺栓的主要缺点是螺栓在其孔内突然滑动。这种螺栓有一个锁定的锥形阀座凸耳，固定在钢段法兰的预钻兼容沉孔内，以提供防滑螺栓-法兰连接。解构是通过使用一个简单的改装扳手从板的顶部拆卸管子来实现的。根据欧洲法规4的建议，通过四次推出试验评估了拟议连接器的机械性能。试验表明，与其他dsc相比，LB-DSC具有较高的抗剪性和刚度，而滑移能力结果将LB-DSC归类为根据欧洲规范4的延性剪切连接器。通过试验验证了改进的非线性有限元模型，并可靠地再现了试验行为。因此，校准的FEM模型被应用于进行广泛的参数分析，以研究混凝土板、灌浆、管和螺栓对LB-DSC结构行为的强度和几何效应。在数值计算和试验结果的基础上，推导了LB-DSC抗剪性能的设计方程。
In order to promote sustainable steel-concrete composite structures, special shear connectors that can facilitate deconstruction are needed. A lockbolt demountable shear connector (LB-DSC), including a grout-filled steel tube embedded in the concrete slab and fastened to a geometrically compatible partial-thread bolt, which is bolted on the steel section’s top flange of a composite beam, was proposed. The main drawback of previous similar demountable bolts is the sudden slip of the bolt inside its hole. This bolt has a locked conical seat lug that is secured inside a predrilled compatible counter-sunk hole in the steel section’s flange to provide a non-slip bolt-flange connection. Deconstruction is achieved by demounting the tube from the top of the slab by unfastening using a simple modified wrench. The mechanical behaviour of the proposed connector is assessed by four pushout tests that were conducted per Eurocode 4 recommendations. The tests showed high shear resistance, and high stiffness as compared to other DSCs, while the slip capacity results classified the LB-DSC as a ductile shear connector according to Eurocode 4. A refined nonlinear finite element model (FEM) was validated through the tests and reliably reproduced the experimental behaviour. Consequently, the calibrated FEM model was applied to carry out extensive parametric analyses to investigate the strength and geometry effects of concrete slab, infilled grout, tube, and bolt on the structural behaviour of the LB-DSC. On the basis of numerical and experimental results, a design equation is derived to predict the shear resistance of the LB-DSC.