STUDY ON MICRO MECHANISM OF DUCTILE FRACTURE

韧性断裂微观机制研究

• 批准号: 03402026
• 负责人: SHIOYA Tadasi
• 金额: $ 20.54万
• 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 (A)
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-03402026/
• 关键词: Ductile Fracture; Void; Tensile Test; Ultrasonic Method; Stress Triaxiality; Constitutive Equation; Effect of Size; Dimple

Microscopic procedure of ductile fracture of material consists of three processes ; 1) Voids nucleation at the second phase particles and/or the triple points of grain boundaries, 2) The voids growth under multi-axial stress states, and 3) The voids coalescences to lead final fracture.In the project, experimental studies are prosecuted on the ductile fracture of mild steel and aluminum specimens under multi-axial stress states. The ultrasonic wave transmission tests are performed measuring the attenuation of the wave during the fracture process in real time to evaluate the voids growth process. The fracture surfaces are observed by scanning electron microscope and optical microscope. The dimples appeared on the fracture surfaces are statistically processed to correlate the stress states and material composition.In the analysis, numerical calculations are carried out to simulate the voids nucleation and growth processes with proposed criteria of nucleation condition and growth rule. The growth process of an isolated void is also analyzed with time-dependent constitutive relation of material. The elongation of the void shape in relation with the initial shape and the applied stress state is examined.The experimental results and the analysis are compared to explain the microscopic process of the ductile fracture qualitatively and quantitatively.

材料延性裂缝的显微镜程序由三个过程组成； 1）在第二阶段颗粒和/或晶界的三个点处的空隙成核，2）在多轴应激状态下的空隙在多轴压力状态下生长，3）空隙凝聚力导致最终骨折。在该项目中，实验研究受到低调钢和铝标志状态下多含量轴向轴测状态的粘液性裂缝的起诉。进行超声波传输测试，以实时测量断裂过程中波的衰减，以评估空隙生长过程。通过扫描电子显微镜和光学显微镜观察断裂表面。骨折表面上出现的酒窝经过统计处理以将应力状态和材料组成相关联。在分析中，进行数值计算以模拟空隙核定和生长过程与拟议的核定条件条件和生长规则的标准。还通过材料的时间依赖性构成关系分析了孤立空隙的生长过程。与初始形状和所施加的应力状态相关的空隙形状的伸长延伸。实验结果和分析进行比较以在质量和定量上解释延性裂缝的显微镜过程。

项目成果

Tetsuya Morimoto: "MEASUREMENT AND ANALYSIS OF MICRO VOIDS NUCLEATION AND GROWS IN DUCTIL FRACTURE OF FCC METAL (APPLICATION OF ULTRASONIC FLOW DETECTION METHOD ON DYNAMIC FRACTURE TEST)" Proceedings of the 1993 Annual Meeting of JSME/MMD. No.73-930. 901-

Tetsuya Morimoto：“FCC金属延展性断裂中微孔洞成核和生长的测量和分析（超声流动检测方法在动态断裂试验中的应用）”JSME/MMD 1993年年会论文集。

Tadashi Shioya: "A MODEL OF ELLIPTICAL VOID GROWTH IN DUCTILE FRACTURE" Pre-print of JSME. No.910-62, Vol.A. 280-282 (1991)

Tadashi Shioya：“延性断裂中的椭圆形空洞生长模型”JSME 预印本。

Tadashi Shioya: "MODEL OF ELLIPTIC VOID GROWTH IN DUCTILE FRACTURE" Transactions of JSME. No.58 (556) A. 75-80 (1992)

Tadashi Shioya：“延性断裂中的椭圆形空洞生长模型”JSME 交易。

塩谷 義: "延性破壊における楕円空孔成長モデル" 日本機械学会第69期全国大会講演会講演論文集A. 280-282 (1991)

Yoshi Shioya：“延性断裂中的椭圆孔生长模型”第69届日本机械工程学会全国会议论文集A.280-282（1991）

森本哲也: "超音波探傷法による延性破壊時の微視空孔発生・成長の測定" Proceedings of the 1994 Annual Meeting of JSME/MMD 平成6年度材料力学部門講演会講演論文集B. 542. 443-444 (1994)

Tetsuya Morimoto：“使用超声波探伤测量韧性断裂过程中微观孔隙生成和生长” JSME/MMD 1994 年年会记录 1994 年材料力学分部讲座记录 B. 542. 443- 444 (1994)