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欧洲规范EC3 Part 1-1第5章[1]允许工程师使用一些先进的有限元分析软件来分析和设计钢结构,如线弹性、刚塑性以及二阶弹塑性整体分析。这3种极不相同的分析方法,能够用于简支、半连续以及连续节点模型中[2]。节点模型根据刚度的不同,可分为铰接、半刚性和刚性模型;按照强度的不同,可分为铰接、部分强度和全强度模型。尽管大多数的工程问题仅仅要求进行线弹性分析,但仍有一些特殊结构可能要求采用高级分析以降低施工成本,例如底层无支撑钢框架结构。在这种结构中,采用半连续节点(具有半刚度和部分强度特性)进行框架分析,会显著增强结构抵抗名义水平荷载、风荷载、整体缺陷、地震作用时的抗侧刚度和强度,因此在控制的水平荷载下计算的横向侧移可能在EC3允许的范围内。在基于性能的抗火设计中,结构抗火工程师可能想利用钢节点潜在的刚度和强度,尤其是有端板节点的钢结构,这是一种最常见的钢结构施工形式。端板可以是部分深度的,或者是延伸端板,涵盖了名义铰接、半刚性和完全刚性节点模型。本文给出了端板节点高温性能研究的一系列数值分析结果;应用基于构件的方法,建立了这些节点在高温下的力学反应计算公式,以及梁腹板剪应力分量、连接处的拉应力和压应力区域的力学模型。基于构件的方法能够考虑钢节点的热约束效应。对已有钢端板节点试验进行了有限元模拟和基于构件的分析表明,2种方法的分析结果与试验结果的偏差都是可接受的,包括热约束效应。
European Directive EC3 Part 1-1, Chapter 5 [1] allows engineers to analyze and design steel structures using advanced FEA software such as linear elasticity, rigid plasticity and second-order elastoplastic overall analysis. These three very different analytical methods can be used in simple support, semi-continuous and continuous node model [2]. According to the different stiffness, the node model can be divided into articulated, semi-rigid and rigid model. According to the different strength, the model can be divided into articulation, partial strength and full strength model. Although most engineering problems require only linear elasticity analysis, there are some special structures that may require advanced analysis to reduce construction costs, such as bottom unsupported steel frame structures. In this structure, the frame analysis using semi-continuous nodes (with semi-rigid and partial-strength characteristics) significantly enhances the structure’s resistance to nominal horizontal loads, wind loads, global defects, lateral rigidity and strength at earthquake action, The calculated lateral displacement under controlled horizontal loads may be within EC3’s allowable range. In performance-based fire-resistant design, structural fire-resistance engineers may want to capitalize on the potential stiffness and strength of steel nodes, especially steel structures with end-plate joints, the most common form of steel construction. The endplates can be partially deep, or extend the endplates, covering nominal-articulated, semi-rigid, and fully rigid node models. In this paper, we give a series of numerical results for the study of the high temperature performance of the end plate joints. By using the method based on the components, the formulas for calculating the mechanical response of these joints at high temperature are established, and the shear stress components, Mechanical model of compressive stress area. The component-based approach considers the thermal constraint effect of steel nodes. Finite element simulation and component-based analysis of the existing steel end plate joints test show that the deviations of the two methods from the experimental results are acceptable, including the thermal constraint effect.