Study on fast crack propagation and arrest behavior of a long crack in steel

钢材长裂纹快速裂纹扩展及止裂行为研究

• 批准号: 03452193
• 负责人: MACHIDA Susumu
• 金额: $ 4.29万
• 依托单位: University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-03452193/
• 关键词: Brittle Crack; Arrest Toughness; Cleavage Fracture Stress; Local Fracture Criterion; Energy Release Rate; HRR Stres Field; Long Crack; 長大ぜい性き裂; 伝播停止; 塑性波拡大モデル; エネルギ-論; 応力論; 伝播シミュレ-ション

Crack arrestability of the material has been measured by a crack arrest toughness K_<ca> based on fracture mechanics concept. Recent experimental studies involving dynamic fracture mechanics analysis show that there is a discrepancy between crack arrest property associated with relatively short arrested crack and that with very long crack. This discrepancy may come from the fact that these analyzes are essentially based on Griffith type energy criterion, which is nothing but a necessary condition. Thus, local stress criterion which might be a sufficient condition should be taken into account in order to clarify the crack arrest behavior.In this study, a simple model for brittle crack propagation and arrest in structural steel is proposed. The hall's model is modified to account for plastic work done in the crack tip region, and HRR stress field is assumed to evaluate crack tip local stress. Based on the model proposed, brittle crack propagation and arrest behaviors simulating both conventional and wide plate experiments are analyzed. The results show that local stress criterion rather than energy criterion controls the crack run-arrest process in structual steel.

材料的止裂性能通过基于断裂力学概念的止裂韧性K_<ca>来测量。最近涉及动态断裂力学分析的实验研究表明，与相对较短的止裂裂纹和与非常长的裂纹相关的止裂性能之间存在差异。这种差异可能来自于这样的事实：这些分析本质上是基于格里菲斯型能量准则，这只是一个必要条件。因此，为了阐明止裂行为，应考虑可能是充分条件的局部应力准则。在本研究中，提出了结构钢中脆性裂纹扩展和止裂的简单模型。修改霍尔模型以考虑裂纹尖端区域所做的塑性功，并假设 HRR 应力场来评估裂纹尖端局部应力。基于所提出的模型，分析了模拟传统和宽板实验的脆性裂纹扩展和停止行为。结果表明，局部应力准则而非能量准则控制着结构钢裂纹的传播-停止过程。

项目成果

町田 進,的場 正明 吉成 仁志,刀根 知佳子: "鋼板の脆性き裂伝播停止挙動に関する一考察" 日本造船学会論文集. 172. (1993)

Susumu Machida、Masaaki Matoba、Hitoshi Yoshinari、Chikako Tone：“钢板脆性裂纹传播停止行为的研究”日本造船学会汇刊 172。（1993 年）。

S.Machida, M.Matoba, H.Yoshinari, K.Tone: "A Modele for Brittle Crack Propagation and Arrest in Atructual Steel" Journal of The Scociety of Naval Architects of Japan. Vol.172. 634-647 (1992)

S.Machida、M.Matoba、H.Yoshinari、K.Tone：“结构钢中脆性裂纹传播和阻止的模型”日本造船学会杂志。