Mesomechanics of nucleation and propagation of small fatigue cracks in metal matrix composites

金属基复合材料中细小疲劳裂纹的形核和扩展的细观力学

• 批准号: 09450047
• 负责人: TANAKA Keisuke
• 金额: $ 6.98万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09450047/
• 关键词: Metal matrix Composite; Fatigue; Crack propagation; Fracture mechanics; Residual stress; Mesomechanics; Crack closure; Small crack; き裂伝ば

1. A new system for the fatigue tests of metal matrix composites in a scanning electron microscope was developed to conduct in-situ observation of initiation and propagation of small fatigue cracks.2. The stress intensity factor for a crack interacting with particles was determined by the finite element method, and used for the prediction of the crack propagation direction and the rate.3. The threshold condition of small fatigue crack propagation was given by the emission of a dislocation from the crack tip or the dislocation annihilation. The propagation behavior of a microstructurally small crack interacting with the grain boundaries was modeled on the basis of continuously distributed dislocation theory combined with the crack closure model. The propagation condition of mechanically small cracks was given by the resistance curve method.4. The published data on the fatigue limit, the threshold stress intensity factor and the effective threshold stress intensity factor of aluminum alloys reinforced and unreinforced by silicon carbide particles or whiskers were correlated to the tensile properties of materials. The reinforcement influenced the tensile strength and also the fatigue properties of materials.

1.研制了一套新的金属基复合材料疲劳试验扫描电镜系统，对疲劳小裂纹的萌生和扩展进行了原位观察.通过有限元方法确定了裂纹与颗粒相互作用时的应力强度因子，并将其用于裂纹扩展方向和速率的预测.疲劳小裂纹扩展的门槛条件由裂纹尖端的位错发射或位错湮灭给出。基于连续分布位错理论和裂纹闭合模型，模拟了微裂纹与晶界相互作用的扩展行为。通过阻力曲线法给出了机械小裂纹的扩展条件。已发表的关于碳化硅颗粒或晶须增强和未增强铝合金的疲劳极限、门槛应力强度因子和有效门槛应力强度因子的数据与材料的拉伸性能相关。钢筋影响材料的抗拉强度和疲劳性能。

项目成果

Y. Akiniwa: "Propagation Behavior of Small Fatigue Cracks in SiCp/Al204 Composites"Proc. Int. Conf. Materials and Mechanics '97 ICM&M'97. 661-666 (1997)

Y. Akiniwa：“SiCp/Al204 复合材料中小疲劳裂纹的扩展行为”Proc。

K.Tanaka: "Mechanics of Small Fatigue Crack Propagation"Small Fatigue Cracks,Elsevier Science Ltd.. 59-71 (1999)

K.Tanaka：“小疲劳裂纹传播的力学”小疲劳裂纹，Elsevier Science Ltd.. 59-71 (1999)

Yoshiaki Akiniwa: "Propagation Behavior of Small Fatigue Cracks Interacting with Particles in MMC" The 3rd inter.Symp.Microstructure Mech.Prop.Engng Materials.67-67 (1997)

Yoshiaki Akiniwa：“MMC 中与颗粒相互作用的小疲劳裂纹的传播行为”第 3 届 inter.Symp.Microstruct Mech.Prop.Engng Materials.67-67 (1997)

K.Tanaka: "Fatigue Thresholds of Discontinuously Reinforced Aluminum Alloys"Proc.7th Int.Fatigue Congress Fatigue '99. 3. 1449-1456 (1999)

K.Tanaka：“非连续强化铝合金的疲劳阈值”Proc.7th Int.Fatigue Conference Fatigue 99。

田中啓介: "炭化ケイ素で強化したアルミニウム合金の疲労限度"日本材料学会,第10回破壊 力学シンポジウム講演論文集. 1-5 (1999)

Keisuke Tanaka：“碳化硅强化铝合金的疲劳极限”第10届断裂力学研讨会论文集，日本材料学会，1-5（1999）