往复荷载下混凝土结构疲劳性能的仿真模拟研究

发布时间：2018-04-12 08:42

本文选题：材料损伤模型 + 仿真模拟　；参考：《重庆大学》2014年硕士论文

【摘要】：基于理论研究的需求，本文将基于能量耗散机制，将研究重点放在用有限元软件ABAQUS建立混凝土结构疲劳性能的仿真分析应用上，通过模拟结构构件荷载-挠度和荷载-切口张开位移关系，并将曲线与试验结果做对比，从而验证理论模型的有效性及实用性。另外，本论文也总结了混凝土构件的疲劳性能理论研究在混凝土结构的疲劳分析方面所取得的一系列进展和疲劳损伤本构模型的研究现状；借鉴相关研究成果，，根据断裂能密度和累积耗散能密度确定材料损伤因子，加卸载应用非线性卸载－线性重加载路径描述，从而建立对混凝土构件单调受拉和往复受拉的疲劳损伤模型。借助ABAQUS有限元软件实现本文模型的有限元移植，从而使理论模型得以在实际工程中应用。首先，混凝土疲劳损伤模型应用Fortran语言编写，成功实现模型中的屈服条件判断、加载和卸载过程描述、非线性的迭代及应力、应变、雅可比矩阵等的一系列数值计算。同时，通过UMAT，将理论模型植入到有限元软件ABAQUS中，建立混凝土构件单轴单调和单轴疲劳损伤加载仿真分析平台。最后，应用此仿真分析平台，对混凝土简支梁在单轴单调和单轴循环加载情况下的力学性能进行模拟。单轴循环加载模拟曲线能较好地体现往复加载过程中混凝土构件的加载刚度退化、卸载残余变形及滞回耗能等行为。本论文模型能很好地模拟混凝土单轴单调、单轴受拉低周循环加载下结构的真实响应，从而使理论模型的有限元移植的合理性得以充分证明，为本理论模型应用于混凝土构件的疲劳损伤分析提供了良好的仿真分析平台。
[Abstract]:Based on the demand of theoretical research, this paper will focus on the application of finite element software ABAQUS to the simulation analysis of fatigue performance of concrete structures based on the energy dissipation mechanism.The relationship between load-deflection and load-notch opening displacement of structural members is simulated, and the curve is compared with the experimental results to verify the validity and practicability of the theoretical model.In addition, this paper also summarizes a series of progress in fatigue analysis of concrete structures and the current research status of fatigue damage constitutive models.According to the fracture energy density and cumulative dissipative energy density, the material damage factors are determined. The nonlinear unloading linear reloading path is used to describe the fatigue damage model of concrete members under monotonic and reciprocating tension.The finite element transplantation of the model is realized with the help of ABAQUS finite element software, so that the theoretical model can be applied in practical engineering.Firstly, the fatigue damage model of concrete is compiled with Fortran language, and a series of numerical calculations of yield condition, loading and unloading process, nonlinear iteration and stress, strain and Jacobian matrix are successfully realized.At the same time, the theoretical model is implanted into the finite element software ABAQUS, and the simulation analysis platform of uniaxial monotone and uniaxial fatigue damage of concrete members is established.Finally, the mechanical properties of simply supported concrete beams under uniaxial monotonic and uniaxial cyclic loading are simulated by using this simulation platform.The simulation curve of uniaxial cyclic loading can well reflect the behavior of load stiffness degradation, unloading residual deformation and hysteretic energy dissipation of concrete members during reciprocating loading.The model can well simulate the real response of concrete under uniaxial monotonic and uniaxial cyclic loading, thus the rationality of the finite element transplantation of the theoretical model can be fully proved.This model provides a good simulation platform for fatigue damage analysis of concrete members.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU37

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