摘要
在极端荷载作用下,结构局部会发生初始损伤.由于初始损伤会在不同结构构件间发生传递,可能会引发结构整体的连续倒塌,造成重大经济损失和人员伤亡.为评估结构的抗连续倒塌能力,通常采用拆除构件法对结构在某一构件发生失效后的整体承载能力进行分析.拆除构件法包括非线性静力Pushdown分析方法和非线性动力分析方法.本文对拆除构件法中非线性动力分析方法的主要影响因素进行研究.选择一个按中国规范设计的五层三跨钢筋混凝土框架结构作为研究对象,分析框架柱失效时长、重力荷载分布形式以及动力加载方式对结构在瞬间失柱条件下非线性动力反应的影响.研究结果表明:柱失效时长对结构非线性动力反应影响显著,当失效时长大约为结构自振周期的0.5倍时,结构非线性反应的动力效应几乎消失;采用不同重力荷载分布形式(满跨分布和受损跨分布)对结构的非线性动力反应影响并不明显;与先加载后移柱的动力加载方式相比,采用先移柱再加载的动力加载方式会放大结构的非线性动力反应,但放大效应有限.
Subjected to extreme load actions, local damages will be initiated.Since the initial local damages can be transferred between different elements, global progressive collapse may be occurred and leads to large economic loss and human casualty.To assess structural resistance of progress collapse, the alternate path method, which includes nonlinear static analysis technique and nonlinear dynamic analysis technique, is commonly used to analyze the global resistance of the damaged structure with one element removed.This paper aims to investigate the main influence factors on the nonlinear dynamic analysis technique used in the alternate path method.A reinforced concrete frame structure that was designed according to the current Chinese codes was selected as the study case.The effects due to different failure time of a frame column, different gravity load distributions, and different applying ways of dynamic loads on the structural dynamic responses caused by a sudden removal of column were examined.The results show that the variation of column failure time has a significant effect on structural nonlinear dynamic response.When the column failure time reaches 0.5 times of structural natural period, the corresponding dynamic effects on structural nonlinear responses almost disappear.Different gravity load distributions （i.e., full bay distribution and damage-bay distribution） do not affect structural nonlinear dynamic responses obviously.Applying dynamic load after column removal consequently amplifies the nonlinear dynamic response of the structure, while the scale of amplification is limited.
出处
《哈尔滨工业大学学报》
EI
CAS
CSCD
北大核心
2017年第6期48-52,共5页
Journal of Harbin Institute of Technology
基金
国家自然科学基金(51408155)
中国博士后科学基金(2014M551251)
黑龙江省博士后基金(LBH-Z14114)
