【摘要】 采用基于显式动力学的有限单元法,通过拆除构件方法,分别对平面框架结构、空间高层框架结构以及框-筒结构的倒塌机制进行数值模拟研究,得到3种结构体系的倒塌机制:平面框架静力作用下倒塌过程中伴随水平构件由“拱机制”到“悬链线机制”的转变;高层空间框架结构倒塌机制与平面框架相似,但由于楼板的作用,倒塌形式、范围与平面框架存在差异;框-筒结构静力作用下的倒塌与空间框架结构相似,而动力加载下,水平构件基本不会形成悬链线机制。此外,分别进行框-筒结构在静力及动力作用下的大比例试验研究,并与数值模拟结果对比,验证模拟方法的准确性及可靠性,并结合数值模拟结果,分析构件的倒塌破坏顺序,验证了框-筒结构倒塌机制。同时,还对采用的线框、整体式、分离式3类数值模型的倒塌模拟的适用性进行了分析。更多还原

【Abstract】 Based on explicit dynamic finite element method and alternate path method,collapse mechanism of several structural forms such as RC plane frame,space high-rise frame structure and high-rise frame-core tube structure were studied according to the collapse numerical simulation analysis.And with detailed comparison and analysis of several aspects,collapse mechanisms of these three structural systems were respectively analysed.The horizontal members of single frame structure would change into ’catenary action’ during the collapse caused by static loads.The space highrise frame structure has the same reaction to the single frame structure while the damage range and deformation situation are different due to the action of slab.The frame-core tube structure is same as the space high-rise frame structure by stcotic loads.While under dynamic loading,’catenary action’ would not happen during the collapse.Besides,large-scale static load test and shaking-table test of the high-rise RC frame-core tube structure were conducted to testify the accuracy and reliability of the numerical simulation methods,and the failure sequence of the members,which verified the collapse mechanisms of RC frame-core tube structure combined with the numerical results.In addition,applicability study of numerical models as wire frame models,integrate models and separate models in collapse simulation was conducted.更多还原