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| 基于改进的片条合成法对有限平板表面裂纹张开位移的研究 |
| Solution of crack opening displacements on surface-cracked finite plate based on the improved slice synthesis method |
| 投稿时间：2024-03-01 修订日期：2024-04-15 |
| DOI： |
| 中文关键词: 改进的片条合成法 表面裂纹 裂纹开口位移 |
| 英文关键词: improved slice synthesis method surface cracks crack opening displacements |
| 基金项目:国家自然科学基金项目（面上项目，重点项目，重大项目） |
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| 中文摘要: |
| 对于船舶结构而言,疲劳载荷下应力集中区域的初始缺陷极易发展成近似为半椭圆形的表面裂纹,而求解裂纹开口位移,对于研究表面疲劳裂纹的扩展机理十分重要。文中提出一种改进的片条合成方法,用于计算弹性条件下有限平板表面裂纹张开位移。首先利用片条合成法得到位移的数值解,再建立不同长宽比、相对裂纹深度比以及裂纹宽度比的网格模型得到有限元解,对比发现之前的片条合成法对表面裂纹形状的适用范围有局限性。分析决定改进方法,通过拟合具体参数并且验证一维和二维一到三次方应力分布下的结果,得到适用的裂纹形状范围：0.05 ≤ c/w ≤ 0.5、0.05 ≤ a/t ≤ 0.4、0.25 ≤ a/c ≤ 1。改进的片条合成法可用于复杂应力分布下有限平板表面裂纹张开位移的计算和残余疲劳寿命预测。 |
| 英文摘要: |
| For ship structures, the initial defects in the stress concentration region under fatigue loading are very likely to develop into surface cracks with an approximate semi-elliptical shape, and solving the crack opening displacement is very important for studying the extension mechanism of surface fatigue cracks. An improved slice synthesis method is proposed for calculating CODs (the crack opening displacements) of surface-cracked finite plates width under elastic conditions. Firstly, the numerical solution is obtained by SSM (the slice synthesis method), and then the finite element solution is obtained by establishing mesh models with different aspect ratios, relative crack depth ratios, and crack width ratios, and the comparison reveals that the previous slice synthesis method has limitations in the range of the application of the surface crack shapes. It is decided to improve the method by fitting the key parameters and verifying the results under different stress distributions to extend the crack shape to 0.05≤c/w≤0.5, 0.05≤a/t≤0.4, and 0.25≤ a/c≤1. The improved slice synthesis method can be used for the calculation of COD and residual fatigue life prediction of finite plate surfaces under complex stress distributions. |
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