考虑界面滑移效应的钢—混凝土组合梁非线性分析

发布时间：2018-09-16 19:13

【摘要】：钢-混凝土组合梁是在钢结构与混凝土结构的基础上发展起来的,综合了钢与混凝土两种不同类型材料的优点,且很大程度上弥补了各自的缺陷。自提出以来就被广泛的应用于工程实际中,并且随着经济与社会的进一步发展,组合结构还将会有更为广阔的发展空间。首先,对已有的钢-混凝土组合梁变形及承载力的计算方法进行了回顾,已有方法中普遍采用了不考虑滑移效应或者将剪力连接件的刚度看成一个常数的假定,这与实际结构的力学行为不符。钢-混凝土组合梁与普通梁最大的区别在于在交界面处存在相对滑移,界面滑移特性主要由剪力连接件的力学性能所决定,本文对栓钉连接件的承载力和荷载-滑移关系曲线的研究成果进行了统计归纳,并通过比较得到了较为合理的用于计算承载力和荷载滑移曲线计算公式。其次,对开源有限元程序OpenSEES进行了介绍,并基于OpenSEES提出了用于钢-混凝土组合梁分析的双层纤维梁模型,其中钢梁和混凝土板分别采用两个独立的纤维梁单元进行模拟,在交界面处设置零长度单元以模拟剪力连接件的荷载-滑移关系,零长度单元的节点分别与钢梁和混凝土板的节点通过刚臂相连以使其能够共同弯曲。采用C++编程语言对OpenSEES程序进行了二次开发,添加了新的单轴材料类MyUniaxialMaterial,该单轴材料模型可以通过自定义曲线上的若干点以直代曲的方式模拟剪力连接件的荷载-滑移非线性关系。最后,利用本文所提出的双层纤维梁单元模型对一组钢-混凝土简支梁和一组钢-混凝土连续组合梁进行加载至破坏的全过程分析,分析结果表明,对于不同形式的钢-混凝土组合梁,本文方法均能对其进行较为准确的模拟。
[Abstract]:Steel-concrete composite beam is developed on the basis of steel structure and concrete structure. It combines the advantages of two different types of materials, steel and concrete, and makes up for their shortcomings to a large extent. Firstly, the existing methods for calculating the deformation and bearing capacity of steel-concrete composite beams are reviewed. The assumption that the stiffness of shear connectors is a constant or not considered is generally adopted in the existing methods, which is not consistent with the mechanical behavior of actual structures. The biggest difference between composite beams and ordinary beams is that there is relative slip at the interface. The interface slip characteristics are mainly determined by the mechanical properties of shear connectors. In this paper, the research results of bearing capacity and load-slip relationship curves of bolted connectors are statistically summarized, and a more reasonable calculation method is obtained by comparison. Secondly, the open-source finite element program OpenSEES is introduced. Based on OpenSEES, a double-layer fiber beam model for the analysis of steel-concrete composite beams is proposed. Two independent fiber beam elements are used to simulate the steel beam and the concrete slab, and zero-length elements are set at the interface. Simulating the load-slip relationship of shear connectors, the joints of zero-length elements are connected with steel beams and concrete slabs through rigid arms to make them bend together. OpenSEES program is redeveloped by C++ programming language, and a new uniaxial material class MyUniaxialMaterial is added. The uniaxial material model can be self-bending. Several points on the curve are defined to simulate the load-slip nonlinear relationship of shear connectors in the form of straight curves. Finally, a set of simply supported steel-concrete beams and a group of continuous composite steel-concrete beams are analyzed by using the double-layer fiber beam element model proposed in this paper. The results show that the load-failure process is different for different kinds of beams. In the form of steel-concrete composite beams, this method can accurately simulate them.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU398.9

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