钢框架—混凝土筒高层混合结构非线性有限元分析

【作者】 许军；

【导师】 陆铁坚；

【作者基本信息】 中南大学 ， 结构工程， 2008， 硕士

【摘要】 本文利用ABAQUS通用有限元程序对外钢框架—内混凝土核心筒高层混合结构进行了非线性有限元分析,对其受力性能和破坏过程进行了数值仿真模拟。分别对四个15层混合结构在顶部位移作用下的静力反应,以及在不同地震作用下的动力反应作了研究、比较,分析表明:1)结构在弹性阶段,由核心筒承担绝大部分水平力,一旦核心筒开裂,钢框架开始承担大部分水平力;特别是结构在地震作用下,随着地震作用的加大,钢框架分担水平力比例不断增大,由七度多遇下分担的10%,到九度罕遇时最高达67%。钢框架起到了抗震第二道防线的作用。2)结构在水平力作用下,混凝土核心筒首先在底部产生开裂,在地震往复作用下,随着损伤不断积累,裂缝不断发展,底层几乎全部开裂。无论在静力还是地震作用下,核心筒开裂后并没有发生脆性破坏马上退出工作,而是承担的水平力在缓慢的增长后出现一较长的平台期,此时核心筒内底部配筋不断屈服。在不同地震作用下,钢框架始终处于弹性阶段,同时结构损伤最严重在底层,但最大层间位移角并没有在第一层。3)通过四个模型分析比较,连梁在剪力墙结构中作为一种耗能结构,而在混合结构中明显地提前并加重了结构的损伤。如果在外钢框架设置加强层作为耗能结构,可以起到既不提前和加大结构损伤,又不致使结构位移加大的作用。更多还原

【Abstract】 Nonlinear finite element analysis was carried out on the steel frame-RC core wall hybrid structure by applying the finite element analysis programe ABAQUS. The analysis was mostly concentrated on the mechanical character and failure process of this structure by the numerical simulation. Both the static response under top displacement and dynamic reaction under different earthquake action was carried out on four 15-storey such structures. The analysis indicated:1) The concrete tube bored most the horizontal force of the structure at the elastic stage, but steel frame carried most part of the horizontal force once the core tube cracked. With the earthquake action intensified, the steel frame carrid more and more horizontal force, which increased from 10% under 7 degree frequent earthquake to 67% under 9 degree rare earthquake. The steel frame acted as the second seismic resistant system.2) Under lateral static force, crackes occurred firstly on the bottom of the core tube . Moreover, almost the whole bottom of the tube cracked with the accumulation of damage under earthquake action. Both under the static and earthquake action, the brittle failure did not occurred on the bottom of the tube. The horizontal force shared by the core tube developed slowly and reached a long platform. On this process, the reinforcement on the bottom of the tube yielded gradually. Under different earthequake action, the steel frame on the structure is always at the elastic stage. The serious damage occurred on the bottom of the structure, but maxium inter-shifts did not on the bottom under earthquqke action.3) By analysis and comparison between the four models, the coupling beam, which acted as an energe consumption component on shear wall structure, obviously aggravate the damage on the hybrid structure. If strengthen layers as a energe consumption was setted up on the steel frame on hybrid strctrure , neither the aggravation of the damage nor the increment of the displacement occurred on the building.更多还原