混凝土单轴受压细观统计损伤本构模型研究

发布时间：2018-01-12 13:07

本文关键词：混凝土单轴受压细观统计损伤本构模型研究　出处：《西安建筑科技大学》2013年硕士论文　论文类型：学位论文

【摘要】：混凝土结构是世界上应用非常广泛的结构形式，它的力学性能和本构关系一直是结构工程界的研究重点。然而混凝土材料具有非常复杂且不确定的特性，迄今为止还未有广泛适用的混凝土本构模型。本文分析混凝土损伤机理，结合混凝土破坏过程，对混凝土细观统计损伤本构模型进行了理论探索。通过比较细观统计损伤力学和宏观连续损伤力学的基本理论及其损伤模型的优缺点，指出基于唯象的细观统计损伤本构模型是混凝土本构研究的新方向。根据非线性科学中的协同学和突变论等有关理论，将混凝土损伤破坏过程分为均匀损伤阶段、临界状态和局部破坏阶段，并将临界状态作为本构模型的最终破坏点。通过对混凝土破坏机理的分析，根据弹脆性平行杆模型的原理思想和Weibull概率密度函数与混凝土强度概率分布函数相似的特点，建立了混凝土单轴受压细观统计损伤本构模型。通过两组经冻融循环作用的混凝土单轴受压试验，确定了本构模型参数，对理论结果和试验结果进行分析，验证其合理性。有限元分析是进行大型结构设计的有效方法，但要使混凝土结构有限元分析结果具有较高的精度，则所选用的本构模型必须准确地描述材料的本构行为。运用ABAQUS有限元分析软件，模拟混凝土棱柱体试件单轴受压的力学性能，将采用本文本构模型的模拟结果分别与试验结果和采用《混凝土规范》推荐的本构模型的模拟结果进行对比，所得结果相似度较高，表明本文本构模型在ABAQUS模拟中可取得较好的结果，，能较准确地模拟混凝土本构行为。
[Abstract]:Concrete structures are widely used in the world, its mechanical properties and constitutive relations have been the focus of research in the field of structural engineering. However, concrete materials have very complex and uncertain characteristics. Up to now, there is no widely applicable concrete constitutive model. In this paper, the damage mechanism of concrete is analyzed, and the meso-statistical damage constitutive model of concrete is theoretically explored in combination with the concrete failure process. By comparing the basic theory of meso-statistical damage mechanics and macroscopic continuous damage mechanics and the advantages and disadvantages of the damage model. It is pointed out that the meso-statistical damage constitutive model based on phenomenology is a new direction of concrete constitutive research. The damage and failure process of concrete is divided into uniform damage stage, critical state and local failure stage, and the critical state is regarded as the ultimate failure point of constitutive model. By analyzing the failure mechanism of concrete, according to the principle of elastic-brittle parallel bar model and the characteristics of Weibull probability density function and concrete strength probability distribution function. A statistical damage constitutive model of concrete under uniaxial compression is established. The parameters of the constitutive model are determined by two groups of uniaxial compression tests of concrete subjected to freeze-thaw cycle. The theoretical and experimental results are analyzed. Verify its rationality. Finite element analysis is an effective method for large-scale structural design, but the result of finite element analysis of concrete structure should have high accuracy. The constitutive model must accurately describe the constitutive behavior of the material. The mechanical properties of concrete prism specimen under uniaxial compression are simulated by ABAQUS finite element analysis software. The simulation results of the constitutive model in this paper are compared with the experimental results and the simulation results of the constitutive model recommended by the concrete Code, and the results have high similarity. It is shown that the constitutive model in this paper can obtain good results in ABAQUS simulation and can simulate the constitutive behavior of concrete more accurately.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU37

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