S-version finite element strategy for accurately evaluating local stress in the vicinity of dynamically propagating crack front in 3D solid
S-version finite element strategy for accurately evaluating local stress in the vicinity of dynamically propagating crack front in 3D solid
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DOI：
10.1016/j.cma.2022.115374
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发表时间：
2022-09
影响因子：
7.2
通讯作者：
Kazuki Shibanuma;Kotaro Kishi;Tianyun He;Naoki Morita;N. Mitsume;Tsutomu Fukui
中科院分区：
文献类型：
--
作者：
Kazuki Shibanuma;Kotaro Kishi;Tianyun He;Naoki Morita;N. Mitsume;Tsutomu Fukui
发展一种精确模拟脆性裂纹扩展现象的数值方法，对于保证大型钢结构的安全至关重要。虽然最近的研究表明，使用局部断裂应力准则作为断裂条件是有效的，但最关键的问题是，在动态扩展裂纹前沿附近的局部应力的方法还没有建立。为了解决这一问题，本文提出了一种战略的基础上的s-版本的有限元法（S-方法）的三维固体中的动态扩展裂纹进行分析。在所提出的策略中，局部网格被定义在附近的裂纹前沿作为一个理想的结构化网格对齐的裂纹前沿方向和裂纹扩展方向，以准确地模拟局部应力场。结合节点力释放法和局部网格更新对动态扩展裂纹前缘进行建模。通过对稳态和动态扩展圆裂纹问题的局部应力和应力强度因子的精度评估，验证了该方法的有效性。结果表明，所提出的策略提供了前所未有的准确性和效率的局部应力评估的问题中的动态裂纹扩展在一个3D固体，而不需要任何复杂的重新网格化程序。因此，所提出的战略有可能作为一个数字框架的基础上，分析动态脆性裂纹扩展问题的局部断裂应力准则为主。
Developing a numerical method to accurately simulate the brittle crack propagation phenomenon is crucial for ensuring the safety of large-scale steel structures. Although recent studies have demonstrated that using the local fracture stress criterion as the fracture condition is effective, the most critical issue is that the methods for evaluating local stress in the vicinity of the dynamically propagating crack front have not been established. To address this, this paper proposes a strategy for analysing a dynamically propagating crack in 3D solids on the basis of the s-version finite element method (s-method). In the proposed strategy, the local mesh is defined in the vicinity of the crack front as an ideal structured mesh aligned with both the crack front direction and crack propagation direction to accurately simulate the local stress field. The dynamically propagating crack front was modelled by a combination of the nodal force release method and local mesh update. The proposed strategy was verified by evaluating the accuracies of the local stress in stationary and dynamically propagating circular crack problems as well as those of the stress intensity factor. The results demonstrate that the proposed strategy provides unprecedented accuracy and efficiency of local stress evaluation in problems of dynamic crack propagation in a 3D solid without requiring any complicated remeshing procedures. Therefore, the proposed strategy has potential as the basis of a numeral framework for analysing dynamic brittle crack propagation problems dominated by the local fracture stress criterion.