基于内聚力模型的耐火材料非线性力学行为模拟

发布时间：2018-04-16 09:10

本文选题：耐火材料 + 细观力学　；参考：《武汉科技大学》2016年硕士论文

【摘要】：耐火材料是一种耐高温的复合材料,是制造炉衬以及高温容器件不可或缺的基础材料,其恶劣的使用环境、复杂的工况条件,严重制约着耐火材料的使用寿命。耐火材料的宏观失效通常是其细观结构的损伤积累、演化导致的,研究其细观损伤形式对宏观力学行为的影响具有十分重要的意义。本文以镁碳质耐火材料为例,采用细观力学方法与有限元方法相结合的手段,对耐火材料的细观界面损伤与宏观力学行为的联系进行了分析研究。具体包括以下几个方面:1.从细观力学出发,采用内聚力模型表征界面开裂过程的力学行为,分析了界面的损伤脱粘机制,定量描述了不同界面性质对界面开裂过程力学行为的影响,为耐火材料界面损伤模型的研究提供了新的思路。2.引入随机序列吸附算法(RSA)的思想,通过采用Python语言对有限元软件进行二次开发,建立了耐火材料多颗粒弥散分布代表性体积单元模型,该模型能够真实地反映颗粒增强耐火材料的细观结构特征。3.在耐火材料多颗粒弥散分布RVE模型受单轴拉伸作用的情况下,通过模拟材料的应力-应变曲线,研究了颗粒相的尺寸、数目等性质对材料宏观非线性力学行为的影响。仿真结果表明,颗粒相的加入提高了材料的宏观有效模量。本文基于细观力学和内聚力模型,建立了耐火材料多颗粒弥散分布界面损伤模型,并模拟了单轴拉伸作用下材料的宏观力学行为,为研究耐火材料细观损伤与宏观非线性力学行为之间的联系奠定了基础。
[Abstract]:Refractory is a kind of high temperature resistant composite material, which is an indispensable basic material for making furnace lining and high temperature container. Its harsh use environment and complex working conditions seriously restrict the service life of refractory.The macroscopical failure of refractories is usually caused by the damage accumulation and evolution of its meso-structure. It is of great significance to study the effect of the meso-damage form on the macroscopic mechanical behavior of refractories.Taking magnesia-carbon refractories as an example, the relationship between meso-interface damage and macroscopic mechanical behavior of refractories is studied by means of the combination of meso-mechanical method and finite element method.This includes the following aspects: 1.Based on the meso-mechanics, the cohesive force model is used to characterize the mechanical behavior of the interface cracking process. The mechanism of damage and debonding of the interface is analyzed, and the influence of different interface properties on the mechanical behavior of the interface cracking process is quantitatively described.It provides a new idea for the study of interface damage model of refractories.By introducing the idea of random sequence adsorption algorithm (rsa), a representative volume element model of multi-particle dispersion distribution of refractories is established by using Python language to develop the finite element software twice.The model can truly reflect the microstructural characteristics of granular reinforced refractories.Under the condition that the RVE model of multi-particle dispersion distribution of refractories is subjected to uniaxial tension, the effects of the size and number of particles on the macroscopic nonlinear mechanical behavior of the materials are studied by simulating the stress-strain curves of the materials.The simulation results show that the addition of particle phase increases the macroscopic effective modulus of the material.Based on the meso-mechanics and cohesion model, the interfacial damage model of multi-particle dispersion distribution of refractories is established, and the macroscopic mechanical behavior of refractories under uniaxial tension is simulated.It lays a foundation for studying the relationship between meso-damage and macroscopic nonlinear mechanical behavior of refractories.
【学位授予单位】：武汉科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TQ175.1

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