Design and Analysis of Moment Connections Using Truss Analogy

本项目的目标是建立钢梁柱节点分析的桁架类比法，并开发一种新的钢框架焊接节点的设计方法和详图实践。现代钢结构建筑遵循经典的伯努利假说。梁的弯矩通过翼缘焊缝传递到柱上，剪力由剪力片承担，这隐含地假设梁柱连接处的梁的承载力与梁在跨中的承载力相同。然而，详细的模型分析表明，剪切片附近的连接区域几乎没有应力，而法兰和法兰焊缝出现了较高的应力集中。本文采用桁架类比法，建立了合理的梁柱节点传力模型。该模型假定节点弯矩通过水平弦力传递，节点剪力由斜杆承担。在弯曲情况下，法兰焊缝将受到复杂的应力状态和过载。桁架类比法表明，节点中的梁必然比跨度中的梁弱。新的设计程序？是基于合理的桁架传力模型。新的设计策略是通过增加一个受弯和一个剪切加固单元来增加节点附近的梁的承载力。已经开展了实现研究目标所需的分析工作。本项目的重点是验证桁架类比方法和改进拟议的梁柱节点设计程序所需的试验研究。总而言之，这些结果将为新连接设计程序和详细实践的全面验证测试奠定基础。

The objectives of this project are to establish the truss analogy approach for analysis of steel beam-to-column connection and to develop a new design procedure and detailing practice for welded connections in steel moment-resisting frames. Modern steel buildings in the wake of the classical Bernoulli hypothesis. The beam bending moment is transferred to the column through the flange welds, while the shear force is taken by the shear tab, which implicitly assumes the capacity of the beam at the beam-to-column connection is the same as the capacity of the beam in the span. However, detailed model analysis showed that the area of the connection near the shear tab is virtually devoid of stresses, while high stress concentrations occurring the flanges and the flange welds. The truss analogy approach is used herein to develop a rational model of force transfer in the beam-to-column connection. The model postulates that the connection bending moment is transferred through the horizontal chord forces, while the connection shear is taken by a diagonal strut. Under bending, the flange welds will be subjected to a complex state of stress and overloaded. The truss analogy approach shows that the beam in the connection is necessarily weaker than in the span. The new design procedure ? is based the rational truss force transfer model. The new design strategy is to increase the capacity of the beam near the connection by adding a flexural and a shear strengthening element. Analytical work needed to achieve the research objectives has been carried out. This project focuses on the experimental research needed to verify the truss analogy approach and refine the proposed beam-to-column connection design procedure. Together, the results will form a base for full-scale proof-testing of the new connection design procedure and detailing practice.