毕业论文移动版

摘要腐蚀是存在于许多行业中的一种常见的损伤形式，例如在大量使用金属材料的船 舶行业和航空航天行业，腐蚀影响着这些行业中机械的使用寿命和整个行业运营的安 全。导致金属材料出现腐蚀的原因有很多，有物理或者化学的因素。不同环境条件下， 腐蚀的形态也不尽相同，点蚀作为一种局部腐蚀形式，由于其隐蔽性，常常在局部造 成很大的应力集中，最终对构件造成巨大的破坏。79831

通过搜集和分析国内外学者在这些方面的研究成果，并结合实际情况，拟定了几 个会影响点蚀处应力分布的因素，包括蚀坑半径，载荷施加方式，深径比，蚀坑间距 离和蚀坑个数。运用有限元软件 ANSYS Workbench 进行数值仿真，得到了蚀坑局部 的应力分布云图。将有限元数值仿真结果代入公式计算得出应力集中系数 SCF，并结 合材料力学，弹性力学和断裂力学所学到的知识，分析蚀坑局部应力分布特点和与这 些影响因素之间的关系。最后给出了各个因素影响下应力集中系数的经验公式，可在 工程实际中用于评估构件的应力集中情况，从而预防点蚀所会带来的严重后果。

毕业论文关键词:腐蚀、点蚀、有限元数值仿真、应力集中系数

Abstract Corrosion is a common form of injury existing in many industries, such as shipbuilding industry and aerospace industry where metal material is widely used。 In these industries, corrosion affects the service life of the machine and the safety of the entire industry。 There are many reasons for the corrosion of metal materials, including physical or chemical factors。 The morphology of the corrosion is different under different environment conditions。 Pitting corrosion as a form of partial corrosion, often leads to great stress concentration due to its concealment, and eventually causes enormous damage to the component。

Several factors which affect the stress distribution of the pitting corrosion are drawn up by collecting and analyzing the research results of domestic and foreign scholars in these areas and combining with the practice situation, including the radius of the pit, the loading mode, the depth to diameter ratio, the distance between the pit and the pit number。 Using finite element software Workbench ANSYS for numerical simulation and the local stress distribution of the corrosion pit was obtained。 The finite element numerical simulation results were substituted into the formula to calculate that the stress concentration factor SCF, and analysis the relationship between corrosion pit local stress distribution characteristics and the influence factors combining with the knowledge of material mechanics, elastic mechanics and fracture mechanics。 Finally, the empirical formula of stress concentration factor under various factors is given, which can be used to evaluate the stress concentration of components in engineering practice, so as to prevent the serious consequences caused by pitting corrosion。

Keyword: Corrosion, Pitting corrosion, Finite element numerical simulation, Stress concentration factor

目录 

第一章 绪论 。 1 

1。1  引言 。 1 

1。2  国内外腐蚀研究现状及存在的问题 。。 2 

1。2。1 国内外腐蚀研究现状  2 

1。2。2 存在的问题  4 

1。3 本文的主要研究内容 。。 4 

第二章 点蚀的有限元应力分析  5 

2。1 应力集中及应力集中系数(SCF) 。。 5

2。2 不同半径蚀坑的有限元应力分析  5 

2。2。1 模型建立 。。 5 

2。2。2 有限元网格划分及加载 。 6