GOALI/Collaborative Research: Strain Gadient Plasticity Modeling to Link Microstructural Non-Local Effects of Dislocation/Interface Interactions with Ductility and Springback

GOALI/合作研究：应变梯度塑性建模将位错/界面相互作用的微观结构非局部效应与延展性和回弹联系起来

• 批准号: 1926662
• 负责人: Michael Miles
• 金额: $ 29.99万
• 依托单位: Brigham Young University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-10-01 至 2023-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1926662&HistoricalAwards=false
• 关键词: GOALI; Collaborative; Research; Strain; Gadient; GOALI; Collaborative; Research; Strain; Gadient

A key component in the strategy to lightweight vehicles for reducing harmful emissions involves the introduction of advanced light alloys across a wide spectrum of vehicle components. However, advanced alloys are typically less ductile than their heavier predecessors and are liable to fracture during the shaping and forming operations. On the other hand, various empirical observations have demonstrated that careful selection of strain (deformation) path during the forming process can significantly delay component failure. Current simulation frameworks do not account for key phenomena at the microstructural level needed to analyze and design better forming processes and to guide alloy selection and development for optimal exploitation of current and forthcoming lightweight materials. By combining novel developments in microscopy and modeling, the critical issue to be explored in this Grant Opportunities for Academic Liaison with Industry (GOALI) research project involves interactions between mobile planes of atoms (dislocations) that facilitate shape change of the component, and microstructural interfaces, such as precipitates and grain boundaries. Barriers to dislocation glide cause atomic pileups, and related backstress effects, that are not considered in traditional models, but can potentially be manipulated to improve overall ductility via careful design of strain paths that occur during forming. The research will be integrated into industrial practice by the industrial partner, Aleris, to deliver potentially transformational capabilities in vehicle lightweighting efforts. As a result of this collaboration, the students involved will also gain an understanding of industrial challenges and drivers. Knowledge derived from the research will be integrated into course curricula for graduate and undergraduate students, while a cloud-based App hosting the developed model will be made available to the broader research community via Materials Resources, LLC. This interdisciplinary project, involving the complementary expertise of two universities and an industrial partner, is driven by the hypothesis that accurate calculation of strain gradients, and related backstress and localization fields, during forming can be used to design strain paths that optimize material ductility, effectively delaying localization/failure in high-strength aluminum (Al) alloy sheets. The team will conceive and implement a novel strain-gradient crystal plasticity finite element model to encapsulate the scientific insights. The model will be guided by a combination of two cutting-edge microstructural techniques that will provide unprecedented detail of the deformation behavior at the relevant length-scale. High-resolution electron backscatter diffraction (HREBSD) will be employed for mapping both geometrically necessary dislocations, accompanying strain gradients, and related backstress for each strain path, while high-resolution digital image correlation (HRDIC) will extract the plastic strain tensor for a complete picture of the deformation. The scientific advances will be applied to warm forming of two high strength alloys with different microstructures, namely AA6022-T4 and AA7050-T6.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.

减少有害排放的轻型车辆策略的关键组成部分是在各种车辆组件中引入高级轻合金。但是，先进的合金通常比其较重的前代产品较少，并且在塑造和成型操作过程中可能会裂缝。另一方面，各种经验观察表明，在形成过程中仔细选择应变（变形）路径可以显着延迟组件故障。当前的仿真框架在分析和设计更好的形成过程所需的微观结构水平上没有考虑关键现象，并指导合金选择和开发以最佳利用当前和即将出现的轻量级材料。通过结合显微镜和建模方面的新发展，在学术联络机构与行业（Goali）研究项目中要探讨的关键问题涉及原子的移动平面（脱位）之间的相互作用，以促进组件形状变化，以及显微结构界面的变化，例如降水和粒度和晶粒界。脱位滑行的障碍会导致原子堆积和相关的背心效应，这些效果在传统模型中不考虑，但可能会通过仔细设计成型过程中发生的应变路径来改善整体延展性。该研究将由工业合作伙伴Aleris纳入工业实践，以在车辆轻型工作中提供潜在的变革能力。由于这种合作，参与的学生还将了解工业挑战和驱动因素。从研究中得出的知识将被整合到研究生和本科生的课程课程中，而托管开发模型的基于云的应用程序将通过Materials Resources，LLC提供给更广泛的研究社区。这个跨学科项目涉及两所大学和工业合作伙伴的补充专业知识，是由假设的假设驱动的：在成型过程中，准确计算应变梯度以及相关的后卫和本地化领域，可用于设计优化材料延展性的应变路径，从而有效地延迟了高含量的铝（Al）Alloy（Al）Alloy Sheers（Al）Alloy Sheers。该团队将构思并实施一种新型的应变梯度晶体可塑性有限元模型，以封装科学见解。该模型将以两种尖端的微观结构技术的组合为指导，这些技术将在相关的长度尺度上提供空前的变形行为细节。高分辨率电子反向散射衍射（HREBSD）将用于绘制每个应变路径的几何必需的脱位，伴随的应变梯度以及相关的背心，而高分辨率的数字图像相关（HRDIC）将提取塑性应变张量，以使塑性应变张量以完整的变形图。科学进步将应用于具有不同微观结构的两种高强度合金的温暖形成，即AA6022-T4和AA7050-T6。这项奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛的影响审查标准来通过评估来通过评估来支持的。