CAREER: Fundamental Studies of Contact Fatigue in Metallic Materials

职业：金属材料接触疲劳的基础研究

• 批准号: 0836763
• 负责人: T. Venkatesh
• 金额: $ 43.95万
• 依托单位: SUNY at Stony Brook
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-02-01 至 2012-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0836763&HistoricalAwards=false
• 关键词: CAREER; Fundamental; Studies; Contact; Fatigue

TECHNICAL: Research is directed towards obtaining a comprehensive understanding of the contact fatigue phenomenon in metallic materials. Through an approach that combines modeling and experimentation, the study will lay the foundation for a framework that explains the four stages of contact fatigue damage, namely, crack initiation, crack propagation under load, crack propagation under the influence of far-field loads, and fast fracture. A unique adhesion-based analytical model will be applied, which together with the formulation of a finite element based numerical model, would provide quantitative guidelines for crack initiation and life prediction. From experiment on materials (single crystalline- and polycrystalline-nickel, and duplex- and lamellar- titanium aluminide) with widely different microstructures, key insights on contact fatigue crack initiation will be obtained. Microstructure characteristic of contact fatigue such as the formation of dislocation structures and/or persistent slip bands preceding and contributing to crack nucleation will be identified through the study of single crystalline nickel. The role of grain-boundaries in inhibiting or enhancing contact fatigue cracking will be discerned through the study of polycrystalline nickel. The effects of phase distribution, i.e., duplex vs. lamellar forms, and domain orientations with respect to contact geometry, on contact fatigue crack initiation and propagation will be evaluated in the titanium aluminide system. NON-TECHNICAL: Research would have scientific and technological impact in the aircraft, automotive, and bio-medical industry. The scientific understanding would help in the development of materials with microstructures that provide enhanced resistance to contact fatigue in safety-critical components in aircraft structures and biomedical implants. The activities will enhance Louisiana State's research base and educational efforts in the field of advanced materials. The research would integrate a three-tier educational plan involving outreach programs addressing K-12 students through the Tulane Science Scholar Program; class-room and research opportunities for undergraduate and graduate students at Tulane and Xavier University (a Historically Black College and University) and dedicated research training for graduate students. Additionally, nearly 100 high school students, 350 undergraduates, 105 minorities, and 25 graduate students would benefit from the effort during the five-year period. An online archive incorporating information about course contents and lectures will also be created to provide easy access to all students and faculty through the department web site. This grant is being co-funded by the Metals Program in DMR and EPSCoR.

技术：研究旨在获得对金属材料中接触疲劳现象的全面了解。通过结合建模和实验的方法，该研究将为一个框架奠定基础，该框架解释了接触疲劳损害的四个阶段快速断裂。将应用一个基于唯一的基于粘附的分析模型，该模型将与有限元的数值模型的配方一起提供定量指南，以进行裂纹启动和寿命预测。通过对具有广泛不同微结构的材料（单晶和多晶尼克以及双晶和层钛合金）的实验，将获得有关接触疲劳裂纹启动的关键见解。接触疲劳的微观结构特征，例如，将通过研究单晶镍的研究来鉴定出在裂纹成核之前的位错结构和/或有助于裂纹成核的持续滑动带的形成。通过研究多晶镍，将分辨出晶界在抑制或增强接触疲劳裂纹中的作用。相位分布的影响，即双链与层状形式，以及有关接触几何形状的域取向，将在钛合金系统中评估接触几何形式，对接触几何形式的启动和传播的影响。 非技术：研究将对飞机，汽车和生物医学行业产生科学和技术影响。科学的理解将有助于开发具有微观结构的材料，这些微观结构可增强飞机结构和生物医学植入物中安全关键部件的接触疲劳的阻力。这些活动将增强路易斯安那州的研究基础和高级材料领域的教育工作。这项研究将整合一项三层教育计划，涉及通过Tulane Science Scholar计划向K-12学生提供针对K-12学生的外展计划；杜兰大学和泽维尔大学（历史悠久的黑人学院和大学）的本科和研究生的课堂和研究机会，以及针对研究生的专门研究培训。此外，在五年期间，将有近100名高中学生，350名本科生，105名少数民族和25名研究生从努力中受益。还将创建有关课程内容和讲座的信息的在线档案，以通过部门网站为所有学生和教师提供便捷的访问。该赠款是由DMR和EPSCOR的金属计划共同资助的。