钢梁—斜撑—支柱型空冷平台弹塑性动力分析

发布时间：2018-04-11 22:36

本文选题：空冷平台结构 + 弹塑性动力分析　；参考：《哈尔滨工业大学》2013年硕士论文

【摘要】：空冷平台是直接空冷火力发电厂的重要结构，其结构形式较为单一，钢梁-斜撑-支柱型空冷平台结构是一种新的结构形式。该体系主要由钢筋混凝土管柱、平台梁系、人字形支撑以及A形架组成，，刚度、质量分布严重不均匀，因此，应对其抗震性能加以足够的重视。而且目前国内外的相关研究很少，深入研究该结构在罕遇地震作用下的损伤特性、变形特性以及受力特性具有重要的工程意义。本文采用有限元数值模拟方法，通过弹塑性时程分析研究钢梁-斜撑-支柱型空冷平台结构在罕遇地震作用下的损伤特性、变形特性以及受力特性，主要完成了以下工作：（1）按照抗震设防烈度和连接假定的组合，分别按7度设防刚接和铰接两个方案来建立空冷平台结构三维有限元数值模型；（2）采用有限元数值模拟方法，对两个方案模型进行模态分析，获得结构的自振特性；（3）进行弹塑性时程分析，研究结构在罕遇地震作用下的损伤特性、变形特性以及受力特性；（4）通过增量时程分析，研究空冷平台结构在罕遇地震作用下的延性。研究表明：结构自由振动以两个正交方向的平动为主且带有一定的扭转效应，需要考虑扭转耦联影响；在对空冷平台支架结构体系进行整体分析时可以不考虑A形架与立柱、钢架的相互作用；钢梁-斜撑-支柱型空冷平台结构的塑性铰主要出现在立柱根部及上部与斜撑连接处上下一定范围内，应有针对性地对容易发生屈服的薄弱部位的变形能力进行加强，使其具有较好的抗震性能；在A形架顶点位移方面，铰接结构方案比刚接结构方案有一定的优势；支撑体系对于空冷平台刚架的加强效果显著，人字形支撑的应用是可行的。最后根据理论分析及数值计算结果提出相关建议：加强立柱与支撑连接部位的构造要求，并且取消斜撑的错位连接或对该连接部位的构造进行特别加强以使节点具有较好的承载能力和变形能力。
[Abstract]:The air cooling platform is an important structure of direct air-cooled power plant, its structure is simple, the steel bracing - pillar type air cooling platform structure is a new structure. This system is mainly composed of reinforced concrete pipe column, beam system, herringbone braced and A shaped frame, stiffness. The mass distribution is seriously uneven, therefore, should be paid enough attention to the seismic performance. But there is little relevant research at home and abroad, further study of the structure with damage characteristics under rare earthquake, the deformation characteristics and stress characteristics has important engineering significance.
In this paper, the finite element numerical simulation is used to study the damage characteristics, deformation characteristics and stress characteristics of the steel beam braced braced air-cooled platform under rare earthquake.
(1) according to the combination of aseismic fortification intensity and connection assumption, three dimensional finite element numerical models of air cooling platform structure are established by two schemes of 7 degrees fortification and rigid connection respectively.
(2) using the finite element numerical simulation method, the modal analysis of the two scheme models is carried out to obtain the self vibration characteristics of the structure.
(3) the elastoplastic time history analysis is carried out to study the damage characteristics, deformation characteristics and stress characteristics of the structure under the action of rare earthquake.
(4) through the incremental time history analysis, the ductility of the air cooled platform structure under the action of rare earthquake is studied.
The research shows that the structural free vibration in two orthogonal directions of the translational and torsional effect with the need to reverse the coupling effect; in the overall analysis of the air cooling platform supporting structure system can be neglected when the A frame and the column, the interaction of steel frame; steel bracing beam plastic hinge pillar type of air cooling platform structure mainly occurred in the upper part and the column root and diagonal joints under a certain range, due to deformation to weak parts prone to yield were strengthened, which has better seismic performance; frame displacement in A, articulated structure scheme has certain advantages than the rigid structure of the program; support system to strengthen the effect of the air cooling platform frame significantly, application of herringbone bracing is feasible.
Finally, according to the results of theoretical analysis and numerical calculation, puts forward relevant suggestions: strengthen the construction of supporting columns and connecting parts of the requirements, and the abolition of the bracing structure of dislocation connection or the connection part of special strengthening so that the node has better bearing capacity and deformation capacity.

【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU398.9

【参考文献】