基于Abaqus-MPC用户子程序的钢筋混凝土结构分析方法

发布时间：2018-03-02 03:01

本文关键词： 钢筋混凝土结构有限元 Abaqus MPC子程序多点约束（MPC）　出处：《重庆交通大学》2013年硕士论文　论文类型：学位论文

【摘要】：钢筋混凝土结构的有限元分析方法一直都是研究的热点问题，其核心问题就是如何处理钢筋和混凝土的连接关系。通用有限元软件Abaqus具有丰富的求解功能和较强的开放结构体系，对于钢筋混凝土结构，其内置的Embedded方法可以模拟钢筋和混凝土的完全粘结关系，多种子程序接口为用户实现个性要求提供了可能。其中多点约束方程（MPC）技术可以用于模拟各种复杂连接关系，既可模拟钢筋和混凝土之间的完全粘结，也可模拟二者的粘结滑移。为模拟钢筋和混凝土之间的连接关系，本文对Abaqus-MPC子程序的实现技术开展研究，具体包括以下内容： ①基于位移协调模式，推导了钢筋节点和混凝土节点的无滑移粘结多点约束关系，并按照MPC子程序的相关要求，编写了处理无滑移粘结的的MPC子程序。并将子程序的计算结果和Abaqus自带的节点耦合方法和嵌入方法进行了对比，对比结果一致。 ②在无滑移粘结的基础上，通过解除相关自由度方向的约束，，得到了无粘结滑移的多点约束关系，同样按照MPC子程序的要求，编写了处理无粘结滑移的MPC子程序，并通过等效荷载的方法和变形关系验证了其正确性。该方法比目前通过添加粘结单元处理无粘结滑移更方便，可以方便的应用到无粘结预应力结构。 ③对于有粘结滑移的情况，提出了结合弹簧单元和多点约束关系的处理方法。即通过在钢筋节点重合的位置建立新的节点，然后将新建节点和所在混凝土单元节点建立多点约束关系，新建节点和钢筋节点之间用弹簧单元粘结。这比直接在邻近节点间建立弹簧连接更精确，比划分单元时要求钢筋节点位置和混凝土节点位置重合更方便。通过本文研究，实现了钢筋混凝土结构钢筋和混凝土之间有粘结、无粘结的分析计算，模拟了钢筋和混凝土不同大小区域连接失效对钢筋混凝梁的影响：对于钢筋混凝土梁，钢筋和混凝土的有效粘结比无粘结情况下的梁的挠度、梁底缘混凝土的主拉应力，梁开裂后裂纹尖端的应力强度因子都更小，并且这种趋势随着粘结失效区域的扩大更加明显。
[Abstract]:The finite element analysis method of reinforced concrete structure has always been a hot topic. The core problem is how to deal with the connection between reinforcement and concrete. The general finite element software Abaqus has abundant solving function and strong open structure system. For reinforced concrete structure, its built-in Embedded method can simulate the complete bond relationship between steel bar and concrete. The multi-point constraint equation (MPC) technique can be used to simulate all kinds of complex connections, which can be used to simulate the complete bond between steel bar and concrete. The bond-slip between them can also be simulated. In order to simulate the connection between steel bar and concrete, this paper studies the implementation technology of Abaqus-MPC subroutine, including the following contents:. 1. Based on the displacement coordination model, the multi-point constraint relationship between reinforced joints and concrete joints without slip bond is derived, and according to the relevant requirements of MPC subroutine, A MPC subroutine dealing with non-slip bond is written, and the calculation results of the subroutine are compared with the nodal coupling method and embedding method of Abaqus. The results are in agreement with each other. 2 on the basis of non-slip bond, the multi-point constraint relation of non-bond slip is obtained by lifting the constraint of the direction of relative degree of freedom. According to the requirement of MPC subroutine, the MPC subroutine is written to deal with the unbonded slip. The validity of the method is verified by the method of equivalent load and the deformation relation. This method is more convenient than the present method by adding bond element to deal with unbonded slip, and it can be applied to unbonded prestressed structure conveniently. (3) for the case of bond-slip, a new method combining spring element and multi-point constraint relation is proposed, that is to say, a new joint is set up in the position where the reinforcement joint is overlapped. Then a multi-point constraint relationship is established between the new node and the node of the concrete element, and the connection between the new node and the reinforced joint is bonded with a spring element, which is more accurate than establishing a spring connection directly between adjacent nodes. It is more convenient than when dividing the unit to require the joint position of steel bar and the position of concrete joint to coincide. Through the research in this paper, the analysis and calculation of bond and unbond between reinforced concrete structure and steel bar are realized, and the influence of the connection failure of steel bar and concrete on the reinforced concrete concrete beam is simulated: for the reinforced concrete beam, The effective bond between steel bar and concrete is smaller than that of the beam without bond, the main tensile stress of concrete at the bottom of the beam and the stress intensity factor at the crack tip of the beam after cracking, and this trend is more obvious with the expansion of the bond failure zone.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU375

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