摘要
钢支撑在轴力作用下会同时发生材料非线性和几何非线性,复杂的力与变形关系是数值模拟过程中的重点与难点。该文基于拟力法的基本理论,提出了支撑非线性滞回行为的计算模型,通过塑性转动铰来模拟由屈曲行为引起的塑性弯曲变形;通过滑动铰来模拟由拉伸屈服和增长效应产生的轴向塑性伸长行为,模型中计及了弹性弯曲变形本身的几何非线性行为。该模型物理意义简单、力学行为明确,在模拟支撑非线性滞回行为的过程中保持初始刚度不变,塑性铰的变形可直观地衡量支撑的屈曲程度。数值模拟与试验结果对比验证了该方法的精确性与适用性。将该模型应用于某钢框架-支撑结构地震反应分析中,计算结果表明:该方法可以模拟支撑在复杂荷载作用下的非线性行为,具备拟力法所特有的精确、高效及稳定等优点。
Material nonlinearity and geometric nonlinearity for steel braces subjected to applied loads occur frequently and the numerical simulation of complex nonlinear force-deformation relationship becomes increasingly important and significant. In this study, a model of nonlinear hysteretic behavior for steel braces was presented based on the force analogy method, which used a plastic hinge and a slide hinge to simulate the behavior of plastic bending deformation produced by buckling and the axial plastic elongation caused by yield and growth effect respectively. In addition, the elastic bending deformation was included in the present model. The proposed method was direct and simple. The initial stiffness was maintained constant when capturing the nonlinear behavior of steel braces. Particularly, the plastic rotation can be acquired and provides a direct evaluation on the buckling behavior state. Verifications showed that the axial force versus axial displacement hysteresis loops agreed reasonably well with the experimental data. The brace model was also implemented in a frame, where inelastic response occurred in both the frame and the braces. The numerical results indicated that the present research can simulate complex nonlinear behavior of steel braces, and is an accurate, efficient, and stable algorithm for conducting dynamic analysis when coupled with the state space formulation.
出处
《工程力学》
EI
CSCD
北大核心
2017年第10期139-148,共10页
Engineering Mechanics
基金
国家自然科学基金优秀青年科学基金项目(51422802)
新世纪优秀人才支持计划项目(NCET-13-0074)
关键词
拟力法
支撑计算模型
局部塑性机制
滞回行为
钢框架-支撑结构
force analogy method
brace numerical model
local plastic mechanism
hysteretic behavior
steelbraced frame
