Multi-Scale Experimental and Computational Investigation of Microscale Origins of Ductile Failure

延性破坏微观起源的多尺度实验和计算研究

• 批准号: 2334678
• 负责人: Allison Beese
• 金额: $ 65.43万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-05-01 至 2027-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2334678&HistoricalAwards=false
• 关键词: Multi; Scale; Experimental; Computational; Investigation

Metals are exposed to countless scenarios in service in which ductile fracture leads to early failure. This award supports fundamental research to understand the origins of this failure type in engineering metals. Using experiments, computational simulations, and data science approaches, the research aims to identify links between key features in the microstructure of metals and their propensity for failure under a wide range of real-world loading conditions. The research findings will enable the more efficient use of existing materials and the design of new materials with tailored microstructures for superior damage tolerance, energy absorption, or fracture performance. These features are key to enabling increased component safety, cost savings, and reduced environmental footprint. The award will provide education and training at undergraduate and graduate levels through student research and will build on an existing partnership with Clark Atlanta University through a faculty/student exchange program and hands-on workshops.The primary goal of this research is to quantitatively determine how multiaxial stress states, modified by local microstructure (grain misorientation and neighborhoods), promotes the development of dislocation structures that result in conditions directly preceding void nucleation in metals. While it is known that engineering measures of failure strain vary with stress state, how local microstructural features alter stress states resulting in fracture initiation is not well understood. The researchers will use experimental measurements (in situ scanning electron microscopy and synchrotron X-ray diffraction) and computational simulations (crystal plasticity and dislocation dynamics) analyzed through advanced regression methods to determine the relative importance and/or coupling of material, microstructural, and stress state features on ductility exhaustion of metals. By unraveling the intertwined roles of these effects, this research will enable the future development of novel fracture criteria that include explicit microstructural descriptions, facilitating the full use of current alloys and the development of superior materials.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

金属在使用过程中会暴露在无数的情况下，其中韧性断裂会导致早期失效。该奖项支持基础研究，以了解工程金属中这种故障类型的起源。通过实验、计算模拟和数据科学方法，该研究旨在确定金属微观结构中的关键特征与其在各种真实负载条件下的失效倾向之间的联系。研究结果将使现有材料的更有效利用和具有定制微观结构的新材料的设计成为可能，以实现上级的损伤容限，能量吸收或断裂性能。这些特性是提高组件安全性、节约成本和减少环境足迹的关键。该奖项将通过学生研究提供本科生和研究生水平的教育和培训，并将通过教师/学生交流计划和实践研讨会与克拉克亚特兰大大学建立现有的合作关系。（晶粒取向不良和邻近区）促进位错结构的发展，导致金属中直接在空穴成核之前的条件。虽然它是已知的，工程措施的破坏应变随应力状态而变化，如何局部微观结构特征改变应力状态，导致断裂的启动还没有得到很好的理解。研究人员将使用实验测量（原位扫描电子显微镜和同步加速器X射线衍射）和计算模拟（晶体塑性和位错动力学），通过先进的回归方法进行分析，以确定材料，微观结构和应力状态特征对金属延展性耗尽的相对重要性和/或耦合。通过解开这些影响的相互交织的作用，这项研究将使未来的新的断裂标准，包括明确的微观结构的描述，促进充分利用现有的合金和上级材料的发展。这一奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。