【作者】 田俊杰；

【导师】 杨伟军； 陈火炎；

【作者基本信息】 长沙理工大学 ， 结构工程， 2004， 硕士

【摘要】 在钢框架的传统理论分析中,总是将框架的梁柱连接假设成理想的铰接或完全刚接。前者意味梁柱之间不能传递弯矩,后者假定框架受载变形后,梁柱间的夹角保持不变。这种理想化的假设大大地简化了钢框架的分析和设计过程,但基于该假定的结构设计可能不安全或偏于保守的,因为在实际工程中的连接是具有半刚性特性的。本文主要针对带双腹板角钢的顶底角钢连接的半刚性连接轻型钢结构框架进行分析研究。 本文对梁柱节点连接的半刚性进行了模拟,采用的模拟方法是在三参数模型基础上,对节点中各角钢的承载力进分析、计算,求得节点的初始连接刚度、极限弯矩承载力,最终得到弯矩-转角关系,达到对节点半刚性模拟的目的。本文对带腹板角钢的顶底角钢连接的框架进行极限承载力分析时,利用几何刚度矩阵来考虑框架结构受力时的几何非线性,在单元内力求解时考虑连接的半刚性影响,文中在对框架进行二阶弹塑性分析时,引进了改进的塑性铰理论求解,文中给出了出现塑性铰后刚度矩阵的处理方法和控制内力不超过屈服面的方法,采用弧长法求解非线性方程组。 最后,本文编制了结构的极限承载力求解程序,该程序能够对单、多层框架进行比较准确的极限承载力计算。更多还原

【Abstract】 In conventional steel frame analysis, the behavior of beam-to-column connections is treated as either pinned or rigid joints entirely. Pinned joints means no moment could be transferred from beam to column, and rigid joints means included angle between beam and column holds the line, from unchanged frame without loads to transfigured frame with loads. These idealized assumptions predigest the analysis and design of steel frame consumedly, but they could induce insecurity or conservative design for in practice engineering joints having semi-rigid characteristic. The dissertation focuses on the study of tip and bottom angle steel linking light steel frames with stomach plank angles.The dissertation imitates the semi-rigid of beam-column joints firstly, the method is based on 3-parameter exponential model, it gets the nonlinear M-θ relationship by the individual joint angle steel load-carrying analysis and calculate to get initial connection stiffness and ultimate moment-carrying capacity of joints, and attains to the purpose of imitating beam-column joint linking semi-rigid. When analyzing the steel frames ultimate load-carrying capacity, the dissertation uses geometric stiffness matrix to think over the frame geometric nonlinear, and thinks over the effect of joints semi-rigid, and introduces the modified plastic hinge model into the second-order inelastic analysis of the structure, and gives the method of how to switch the stiffness matrix after appearing plastic hinge and how to control internal force under the yielding surface. The dissertation uses arc length-method solve the nonlinear equation group.At the end, the dissertation develop a program to solve the ultimate load-carrying capacity of frames, which can be used to calculate the maximum strength of the multistory steel structures accurately.更多还原