吴金波,孙奇,江晓禹.基于分布位错法对涂层裂纹力学行为的研究[J].表面技术,2024,53(7):171-179.
WU Jinbo,SUN Qi,JIANG Xiaoyu.Mechanical Behavior of Coating Cracks Based on Distributed Dislocation Method[J].Surface Technology,2024,53(7):171-179 |
| 基于分布位错法对涂层裂纹力学行为的研究 |
| Mechanical Behavior of Coating Cracks Based on Distributed Dislocation Method |
| 投稿时间：2023-04-11 修订日期：2023-08-10 |
| DOI：10.16490/j.cnki.issn.1001-3660.2024.07.018 |
| 中文关键词: 涂层裂纹 分布位错 应力强度因子 界面应力 扩展方向 |
| 英文关键词:coating crack distributed dislocation stress intensity factor interfacial stress propagation direction |
| 基金项目:国家自然科学基金(11472230) |
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| 中文摘要: |
| 目的 在单轴拉伸载荷下，用理论方法求解弹性涂层中裂纹的力学性质和相互影响。方法 根据叠加原理，将问题分为2个子问题，使用分布位错原理求解裂纹问题，将裂纹建模为沿裂纹线分布的位错阵列，叠加后使用数值求解方法进行求解。结果 得到了不同涂层模量、不同裂纹长度下表面裂纹尖端的应力强度因子(SIF)和涂层界面应力。涂层与基底模量相差越大，表面裂纹越长，其界面应力越大。计算了不同方位下的微裂纹对表面裂纹的影响，给出了60°倾角微裂纹、2l/h=0.2和2l/h=0.04表面裂纹以及2a/h=0.01和2a/h=0.018表面裂纹的影响区域。分析了涂层内部倾斜裂纹对表面裂纹应力强度因子和扩展角的影响。内部倾斜裂纹尖端对表面裂纹尖端的等效应力强度因子(ESIF)有增强作用，两侧有减弱作用。结论 较硬涂层对表面裂纹的扩展有增强作用，裂纹越长，受涂层模量对其应力强度因子的影响越大。微裂纹对表面裂纹的影响跟微裂纹位置、方向、长度和表面裂纹长度有关。表面裂纹附近的倾斜裂纹对表面裂纹的扩展具有吸引作用。 |
| 英文摘要: |
| In the preparation of coating materials, defects such as pores and microcracks are often produced in the coating and the interface, and the propagation of cracks in the coating is a way of coating failure. In this paper, the mechanical properties and interaction of surface cracks and inner cracks in elastic coatings under uniaxial tensile load are solved theoretically. The method is also suitable for multiple cracks. According to the superposition principle, the problem becomes two sub-problems. The distributed dislocation principle was adopted for the crack problem. After superposition, the integral equation was solved by numerical solution method, and the dislocation density function was solved. The stress intensity factor (SIF) at the crack tip was calculated by interpolation method, and the propagation direction of the crack was calculated by maximum circumferential stress theory. The stress field of the model was obtained by substituting the dislocation density function back into the integral equation under global coordinates. The method was verified by setting the same modulus of the coating and the substrate and degrading the model to an infinite semi-planar sub-surface crack problem. |
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