Development of the Method of Crack Growth Analysis and Its Applications

裂纹扩展分析方法的发展及其应用

• 批准号: 12650104
• 负责人: NISITANI Hironobu
• 金额: $ 2.3万
• 依托单位: Kyushu Sangyo University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12650104/
• 关键词: Crack growth simulation; Compressive shear fracture; Linear Fracture mechanics; Wing crack; Body Force Method; ウイングき裂; 多数き裂群; き裂伝ぱ; き裂屈折条件; ぜい性破壊; シミュレーション; 弾性; 破壊力学; 破壊基準

A typical fracture of machines and structures is preceded by a propagation and coalescence of minute cracks that exist inside the body in advance or outbreak during life time. Therefore, in the prediction of the behavior of fracture, it is important to grasp a path of crack propagation and how to coalesce themselves during growth under given loading conditions.In order to realize an ideal simulation of crack propagation, the following two conditions are essential. The first is to use an adequate numerical scheme which can calculate the singular stress fields at the tip of an arbitrary shaped crack as accurately and effectively as possible.The second is to choose an adequate criterion that predicts the direction of crack propagation. In a conventional analysis, a maximum principle stress criterion or a local symmetry criterion is employed usually. The farmer enables relatively high-efficiency prediction but sometimes leads poor numerical results. On the other hand, the latter is reliabl … More e but too expensive to apply the crack propagation simulation among multiple cracks.In order to overcome the first condition, the Body Force Method, known as a powerful numerical method especially for crack problems is employed. The developed system can treat all two-dimensional crack problems essentially even in a case for extremely complex crack geometry where a number of branches and kink points are involved. In order to overcome the second condition, new prediction scheme for the direction of further crack propagation using a resultant force at the crack tip field is proposed. Through the numerical tests for many kinds of crack propagation problems, it was verified that the proposed criterion is much effective and provides highly accurate solution than ordinary methods.The developed crack propagation analysis system was applied many kinds of problems such as the crack propagation in a standard specimens, crack coalescence problem in a rectangular plates and failure simulation among multiple cracks in brittle materials under compressive stress. Less

机器和结构的典型断裂发生之前，是由预先存在于体内或在生命周期中突然爆发的微小裂缝的扩展和合并引起的。因此，在预测断裂行为时，掌握裂纹扩展路径以及在给定载荷条件下裂纹扩展过程中如何合并是非常重要的。为了实现理想的裂纹扩展模拟，必须满足以下两个条件。一是采用适当的数值格式，尽可能准确有效地计算任意形状裂纹尖端的奇异应力场。二是选择一个合适的准则来预测裂纹的扩展方向。在传统分析中，通常采用最大主应力判据或局部对称判据。农民可以实现相对高效的预测，但有时导致较差的数值结果。另一方面，后者是可靠的，但对于多裂纹间的裂纹扩展模拟来说，方法更方便，但成本过高。为了克服第一个条件，采用了专门研究裂纹问题的强大数值方法——体力法。所开发的系统基本上可以处理所有二维裂纹问题，即使是在涉及许多分支和扭结点的极其复杂的裂纹几何形状的情况下。为了克服第二个条件，提出了利用裂纹尖端场合力预测裂纹进一步扩展方向的新方案。通过对多种裂纹扩展问题的数值试验，验证了该准则的有效性，并提供了比普通方法更精确的解。所开发的裂纹扩展分析系统可应用于标准试样中的裂纹扩展问题、矩形板中的裂纹合并问题以及脆性材料在压应力作用下的多裂纹破坏模拟等多种问题。少

项目成果

H.Nisitani, T.Teranisi: "KI Value of a Circumferential Crack Emanating from an Ellipsoidal Cavity Obtained by the Crack Tip Stress Method in FEM"Advances in Fracture and Damage Mechanics. II. 141-148 (2001)

H.Nisitani、T.Teranisi：“通过 FEM 中的裂纹尖端应力方法获得的椭圆体空腔发出的圆周裂纹的 KI 值”断裂和损伤力学的进展。

H.Nisitani, T.Teranisi, A.Saimoto: "Examination of the Crack Tip Stress Method in FEM Base on Body Force Method"Advances in Boundary Element Techniques. II. 387-394 (2001)

H.Nisitani、T.Teranisi、A.Saimoto：“基于体力法的有限元中裂纹尖端应力法的检查”边界元技术的进展。

H.Nisitani, T.Teranisi: "Highly Accurate Values of KI and KII of Axially Symmetrical Cracked Body Subjected to Tension Obtained by FEM"Damage and Fracture Mechanics VI. 461-469 (2000)

H.Nisitani，T.Teranisi：“通过有限元法获得的受拉轴对称裂纹体的 KI 和 KII 的高精度值”损伤与断裂力学 VI。

H.Nisitani, T.Teranisi: "KI Value of a Circumferential Crack Emanating from an Ellipsoidal Cavity Obtained by the Crack Tip Stress Method in FEM"Advances in Fracture and Damage Mechanics II. 141-148 (2001)

H.Nisitani、T.Teranisi：“通过 FEM 中的裂纹尖端应力法获得的椭圆体空腔发出的圆周裂纹的 KI 值”断裂和损伤力学的进展 II。

H Nisitani, T Teranishi, A Sairnoto: "Examination of the Crack Tip Stress Method in FEM Based on Body Force Method"Advances in Boundary Element Techniques II. 387-394 (2001)

H Nisitani、T Teranishi、A Sairnoto：“基于体力法的有限元中裂纹尖端应力法的检验”边界元技术的进展 II。