轻钢框架—加气混凝土砌块组合墙体抗侧性能有限元分析

发布时间：2018-03-10 20:12

本文选题：轻钢框架　切入点：蒸压加气混凝土砌块　出处：《武汉理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：格构轻钢是近年来出现的一种新的轻钢龙骨体系,以其自重轻、可高度工业化、工期短、湿作业少、抗震性好、造价低、绿色环保可回收等优点,而越来越多为人所知,并被推广应用于低、多层房屋住宅中。这种结构体系墙体仍由密排的格构片柱和格构方柱组成,相对于钢筋混凝土结构有不密实的缺点,且管壁较薄容易发生局部或整体失稳,从而降低了其极限承载力。本文为解决格构轻钢龙骨体系墙体的上述两点不足,将墙体中格构方柱组成的格构轻钢框架、蒸压加气混凝土砌体及包裹格构轻钢框架的发泡混凝土组合成一种新型轻钢框架-蒸压加气混凝土砌块组合墙体。本文以轻钢框架-蒸压加气混凝土砌块组合墙体为研究对象,首先简要地介绍了墙体的组成、做法及特点。为了解不同材料的力学性能,论文在展开理论研究之前,对蒸压加气混凝土砌块、发泡混凝土、砂浆和钢材均做了弹性模量和极限抗压强度试验,在参考相关文献和理论成果的基础上得到了四种材料的受拉和受压应力应变关系。论文利用ABAQUS有限元软件,分别建立了格构轻钢框架及组合墙体的有限元模型,其中,格构轻钢框架中的钢管和连接件分别简化为梁单元。为简化计算,仅沿厚度方向取出一半的组合墙体进行建模分析。组合墙体建模时,格构框架中的钢管和连接件简化成梁单元,并嵌固于二维实体的发泡混凝土中。若干蒸压混凝土砌块也被分别简化为二维实体单元,通过模拟砂浆的cohesive单元连接。而发泡混凝土和蒸压混凝土砌块之间直接通过merge命令组合在一起。在论文提出的轻钢框架-蒸压加气混凝土砌体组合墙体简化计算模型的基础上,对组合墙体进行了水平荷载作用下的抗侧刚度和承载力的分析,并与试验结果进行了对比,从而验证组合墙体理论建模方法的合理性。论文在组合墙体有限元模型的基础上,分析了影响组合墙体抗侧承载力和抗侧刚度的若干因素,包括蒸压加气混凝土砌块、砂浆和发泡混凝土的强度等级以及轻钢框架钢管的厚度。结果表明:轻钢框架-砌块组合墙体相比于轻钢框架的抗侧极限承载力和刚度均有显著提高;提高蒸压加气混凝土砌块、发泡混凝土和砂浆的强度等级能明显提高组合墙体的抗侧极限承载力,但对墙体抗侧刚度提高不明显;增大轻钢框架钢管的厚度能明显提高组合墙体的抗侧刚度,但对组合墙体的侧向极限承载力的提高不明显。本文对轻钢框架-蒸压混凝土砌体组合墙体进行了有限元分析,研究成果为这种组合墙体的进一步研究提供参考,为工程应用提供理论依据。
[Abstract]:Lattice light steel is a new kind of light steel keel system which appears in recent years. It is more and more known for its advantages of light weight, high industrialization, short construction period, less wet operation, good seismic resistance, low cost, green environmental protection and recoverable, etc. The wall of this kind of structure system is still composed of dense lattice column and lattice square column, which has the disadvantage of not compactness compared with reinforced concrete structure, and the thin pipe wall is prone to local or global instability. Therefore, the ultimate bearing capacity is reduced. In order to solve the above two deficiencies of the lattice light steel keel wall, the lattice light steel frame composed of the lattice square column in the wall is used in this paper. A new type of light steel frame-autoclaved aerated concrete block composite wall is formed by the combination of autoclaved aerated concrete masonry and foamed concrete encased in lattice light steel frame. This paper takes the light steel frame-autoclaved aerated concrete block composite wall as the research object. In order to understand the mechanical properties of different materials, the autoclaved aerated concrete block and foamed concrete were studied before the theoretical study. The elastic modulus and ultimate compressive strength of mortar and steel are tested. Based on the references and theoretical results, the relationship between tensile and compressive stress and strain of four kinds of materials is obtained. The ABAQUS finite element software is used in this paper. The finite element models of lattice light steel frame and composite wall are established respectively, in which the steel pipe and the connectors in the lattice light steel frame are respectively simplified as beam elements. Only half of the composite walls are taken out along the thickness direction for modeling and analysis. When the composite walls are modeled, the steel pipes and connectors in the lattice frame are simplified into beam elements. A number of autoclaved concrete blocks are also reduced to two-dimensional solid elements. By simulating the cohesive element connection of mortar, the foamed concrete and autoclaved concrete block are directly combined by merge command. Based on the simplified calculation model of lightweight steel frame-autoclaved aerated concrete masonry masonry wall proposed in this paper, The lateral stiffness and bearing capacity of composite wall under horizontal load are analyzed and compared with the experimental results to verify the rationality of the theoretical modeling method of composite wall. Some factors affecting lateral bearing capacity and lateral stiffness of composite wall, including autoclaved aerated concrete block, are analyzed. The strength grade of mortar and foamed concrete and the thickness of light steel frame steel tube. The results show that the ultimate lateral bearing capacity and stiffness of light steel frame-block composite wall are significantly higher than those of light steel frame. Increasing the strength grade of autoclaved aerated concrete block foamed concrete and mortar can obviously improve the ultimate lateral bearing capacity of the composite wall but the anti-lateral stiffness of the wall is not obvious. Increasing the thickness of light steel frame steel tube can obviously improve the lateral stiffness of the composite wall, but the lateral ultimate bearing capacity of the composite wall is not obviously improved. In this paper, the finite element analysis of the light steel frame-autoclaved concrete masonry composite wall is carried out. The research results provide a reference for the further study of this composite wall and theoretical basis for engineering application.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU398

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