碳纳米管增强镁基复合材料应力场有限元分析

发布时间：2018-03-08 12:40

本文选题：镁基复合材料　切入点：碳纳米管　出处：《沈阳工业大学》2016年硕士论文　论文类型：学位论文

【摘要】：镁基复合材料是近年来发展较快的新型高强轻质复合材料。具有高导电和导热率,高比模量、优良的阻尼减震性能及力学性能,硬度高,耐磨性良好。不仅是航空航天等广泛应用的结构材料,还可作为飞机部件,船体外壳,承力结构,支撑缓冲的基础材料,是一种具有广阔发展前景的新型材料。金属基复合材料传统的增强相包括:纤维,晶须,颗粒,而由于碳纳米管具有高强度和低密度,以及良好的稳定性。因此它有可能是一种理想的增强相材料,近年来碳纳米管也越来越引起研究界的重视。而作为增强相的碳纳米管尺寸非常小,实验操作比较困难。因此可用有限元分析软件研究复合材料的力学性能,以拓展碳纳米管增强体复合材料的应用。本文主要运用密度泛函和连续介质力学的理论以及相对应的软件MS和ANSYS解决碳纳米管增强镁基复合材料力学性能的计算。课题研究主要包括以下内容:(1)本文第一部分研究内容采用模拟软件MS,基于密度泛函理论的量子力学程序CASTEP模块,对碳纳米管含有异质原子,预设缺陷及不同长径比时,对其进行相同程度的拉伸形变,计算模型的结合能,分析其稳定性及其对碳纳米管的力学性能的影响。发现在相同拉伸载荷下,本征碳纳米管稳定性最弱。(2)本文第二部分利用连续介质力学的理论,用有限元软件ANSYS建造含不同长径比和不同相位角的碳纳米管增强镁基复合材料模型在拉伸载荷下对复合材料应力分布影响。发现应力以碳纳米管的轴向呈近似对称分布,长径比为5的模型及两个碳纳米管轴向分布呈60?时,最大应力值最小,表明在相同拉伸载荷下,该模型力学性能最好,最不易破坏。(3)本文第三部分研究复合材料含有缺陷时拉伸载荷对复合材料的应力分布影响。分别选取无缺陷,镁基含有竖向缺陷,横向缺陷和环向缺陷的简化模型。发现复合材料在受到拉伸载荷时,竖向缺陷的模型最易断裂,而镁基含有环向缺陷时最不易破坏。
[Abstract]:Magnesium matrix composite is a new type of high strength lightweight composite materials developed rapidly in recent years. It has high conductivity and high thermal conductivity, high specific modulus, damping properties and mechanical properties, excellent hardness, good abrasion resistance. Not only is the structural material widely used in aerospace, also can be used as aircraft components, hull, bearing the basic structure, material support buffer, is a kind of new material and has broad prospects for development. The traditional reinforced metal matrix composite material includes: fiber, whisker, particles, and the carbon nanotubes with high strength and low density, and good stability. So it may be an ideal reinforcement materials. In recent years, carbon nanotube has attracted the attention of the research community. But as the reinforcement of carbon nanotube size is very small, the operation is more difficult. Therefore the available finite element analysis software to study the composite force School performance, in order to expand the application of carbon nanotube reinforced composites. This paper mainly uses density functional theory and the theory of continuum mechanics and the corresponding software MS and ANSYS to solve the calculation of carbon nanotube reinforced mechanical properties of magnesium matrix composite. The research mainly includes the following contents: (1) the first part of this paper to study the simulation the software of MS, quantum mechanics program CASTEP module based on the density functional theory of carbon nanotubes containing hetero atoms, preset defects and different slenderness ratio, tensile deformation on the same level, combined with the calculation model, it analyzes the influence of stability and mechanical properties of carbon nanotubes. Found in the same under tensile load the intrinsic stability of carbon nanotubes, the weakest. (2) the theory of using continuum mechanics in the second, using the finite element software ANSYS built with different slenderness ratio and different phase The model of carbon nanotubes reinforced angle magnesium matrix composite stress of composite under tensile load. It is found that the stress distribution influence of carbon nanotubes is approximate to the axial symmetric distribution, the slenderness ratio is 5 and the model two carbon nanotube axial distribution is 60?, the maximum stress value of the minimum, shows that in the same stretch under the load, the model of the best mechanical properties, the most difficult to destroy. (3) the third part of this paper studies a composite material containing defects when the tensile load of the composite stress distribution were selected. No defects, magnesium containing vertical defects, transverse defects and circumferential defects of the simplified model. The composite materials under tension when the loads vertical defect model is the most easy to fracture, and the magnesium matrix with circumferential defect is the most difficult to destroy.

【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TB333

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