功能梯度涂层接触问题的实验分析与有限元模拟

发布时间：2018-04-25 16:28

本文选题：功能梯度涂层 + 压痕实验　；参考：《内蒙古工业大学》2015年硕士论文

【摘要】：功能梯度材料所具有的独特性质以及潜在的研究空间,使得其成为研究领域的热门学科。由于功能梯度材料用作涂层可抑制接触损伤和破坏,受到力学工作者的广泛关注。本文主要采用实验方法和有限元仿真技术对功能梯度涂层三维接触问题进行研究。首先,应用布氏硬度计分别对不同材料模型进行了压痕实验,实验得出了均匀材料模型与梯度材料模型的压力-压痕半径关系曲线;其次,应用ABAQUS有限元软件计算功能梯度涂层分别在集中荷载和圆形均布荷载作用下表面位移,分别考虑了功能梯度材料弹性模量按照不同函数形式变化时的情况。最后,应用ABAQUS软件分析了功能梯度涂层在刚性球形压头作用下的三维无摩擦接触问题,并将计算结果与公式解进行了比较;同时分析了不同弹性模量变化形式对接触表面应力变化的影响。研究结果表明:(1)布氏硬度实验结果表明:采用不同的材料组合模型对压力-压痕曲线具有明显的影响。其中,材料弹性模量的梯度变化是压痕实验产生重要影响的主要因素。(2)利用ABAQUS软件可有效的模拟功能梯度材料涂层的表面沉降问题。同时ABAQUS软件可以模拟材料参数按照不同函数形式变化的功能梯度材料模型。通过有限元计算表明,材料弹性参数的变化形式对于梯度层表面在集中和均布载荷作用下的位移沉降产生影响。(3)功能梯度涂层在球形压头作用下时,指数函数形式变化的梯度材料涂层,其压痕半径、压入深度以及接触应力都会随弹性模量的减小呈减小趋势。固定涂层上下表面弹性模量比值,同时将弹性模量分别按照指数函数、线性函数、余弦函数变化时,其压痕半径、压入深度以及接触应力会呈减小趋势。本文的研究结果对于功能梯度涂层的接触问题研究具有一定的理论价值;同时,本文的研究结果对于梯度材料的工程应用具有一定的指导意义。
[Abstract]:Due to its unique properties and potential research space, functionally graded materials (FGM) have become a hot subject in the field of research. As functionally graded materials (FGM) as coatings can inhibit contact damage and damage, they have attracted extensive attention from mechanics workers. In this paper, the three-dimensional contact problem of functionally gradient coatings is studied by means of experimental method and finite element simulation technique. Firstly, the indentation experiments of different material models are carried out by using Brinell hardness meter, and the curves of pressure-indentation radius between uniform material model and gradient material model are obtained. The surface displacement of functionally graded coatings under concentrated load and circular uniform load was calculated by ABAQUS software. The elastic modulus of functionally graded materials varied according to different function forms. Finally, the three-dimension friction-free contact problem of functionally graded coating under the action of rigid spherical head is analyzed by ABAQUS software, and the results are compared with the formula solution. At the same time, the influence of different forms of elastic modulus on the stress change of contact surface is analyzed. The results show that the different material combination models have obvious influence on the pressure-indentation curve. The gradient change of elastic modulus of materials is the main factor influencing indentation test. (2) ABAQUS software can be used to simulate the surface subsidence of functionally graded material coating effectively. At the same time, the ABAQUS software can simulate the functionally graded material model in which the material parameters change according to different function forms. The finite element calculation shows that the change of elastic parameters of the material has an effect on the displacement settlement of the gradient layer surface under concentrated and uniform loads. The indentation radius, indentation depth and contact stress of gradient material coating with exponential function change tend to decrease with the decrease of elastic modulus. The indentation radius, indentation depth and contact stress will decrease when the elastic modulus is changed according to exponential function, linear function and cosine function respectively. The results of this paper have certain theoretical value for the study of the contact problem of functionally graded coatings, and also have certain guiding significance for the engineering application of gradient materials.
【学位授予单位】：内蒙古工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ630.1;TB34

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