论文部分内容阅读
目前,钢混凝土组合梁由于其具有截面高度小、自重轻、延性好等优点而广泛应用于高层建筑和桥梁结构中。钢混凝土组合梁中,钢梁和混凝土板通过剪力连接件共同作用,钢混凝土组合梁的性能很大程度上依赖于剪力连接件的性能,因此剪力连接件是组合梁中的关键部位。栓钉是目前最常用的柔性剪力连接件。本文采用有限元软件ABAQUS,较系统地研究了高温下组合梁中栓钉破坏形态、破坏机理、抗剪承载力和荷载—滑移规律性能,为高温下组合梁抗火性能研究提供基础。模型中混凝土、栓钉和钢梁采用实体单元模拟,材料的力学特性和热工特性参数根据欧洲规范(EN 1994-1-2)。本文先用文献中的试验结果验证了数值模型的可靠性,并进一步研究了不同栓钉直径和不同混凝土强度等级时的高温下栓钉承栽力折减系数。研究表明,欧洲规范中高温下栓钉承栽力的计算公式是合理的,能较准确地预测栓钉在高温下的承栽力。
At present, steel-concrete composite beams are widely used in high-rise buildings and bridges because of their advantages of small cross-section height, light weight and good ductility. In the steel-concrete composite beam, the steel beam and the concrete slab act together through the shear connection, and the performance of the steel-concrete composite beam depends largely on the performance of the shear connection. Therefore, the shear connection is the key part in the composite beam . Pegs are the most commonly used flexible shear connectors. In this paper, finite element software ABAQUS is used to systematically study the failure mode, failure mechanism, shear capacity and load-slip regularity of pegs in composite beams at high temperature, and provide a basis for the study of fire resistance of composite beams at high temperature. Concrete, studs and steel beams are modeled as solid elements in the model. The mechanical and thermal properties of the material are in accordance with the European Directive (EN 1994-1-2). In this paper, the reliability of the numerical model is verified by the experimental results in the literature, and the reduction factor of the peg bearing capacity under high temperature with different peg diameters and different concrete strength grades is further studied. The research shows that the calculation formula of the dowel bearing capacity under the European standard is reasonable and can accurately predict the bearing capacity of the pegs at high temperature.