Description of Strengthening through Internal Stress Development in Rolled Structured Metals

通过轧制结构金属中的内应力发展进行强化的描述

• 批准号: 0423304
• 负责人: Amit Acharya
• 金额: $ 30.3万
• 依托单位: Carnegie-Mellon University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0423304&HistoricalAwards=false
• 关键词: Description; Strengthening; through; Internal; Stress

The objective of this research is to study the internal stress and relaxation mechanisms in the plasticity of polycrystalline metals. The research approach is to complement traditional formulations of polycrystal plasticity with a recently developed model of field dislocation mechanics that accounts for the internal stress and evolution of the observable polar dislocation density (at the desired scale of resolution) in a mechanically rigorous manner. The theory is applied to the technologically important problem of understanding yield upon load path change to enable predictive modeling of springback and in-service stress relaxation in rolled metal products. This project provides a new step in providing a low-cost means of predicting yield and reverse yield for any choice of loading and unloading path direction, respectively. The result will give a simulation capability embracing bulk crystallographic slip in processing, inelasticity in unloading, and prediction of strength in the final product. Light weighting of automobiles through use of aluminum alloys remains a cost-effective and timely means of reducing greenhouse gas emissions as well as improving fuel efficiency. Both issues have significant national and international economic and environmental ramifications. Understanding of the springback and stress relaxation in stamped aluminum sheet is essential to design of tooling for production of autobody panels leading to light weighting. The research enhances the scientific workforce through the education of graduate students and enriches education materials.This Grant Opportunities for Academic Liaison with Industry (GOALI) grant provides an opportunity for a joint research effort between Carnegie Mellon University and an industrial partner, ABAQUS, Inc (Rhode Island). The project leverages expertise from ABAQUS, Inc. in the form of graduate student advising and integration between our research result and the commercial FEM software package, ABAQUS.

本研究的目的是研究多晶金属塑性中的内应力和松弛机制。该研究方法是用最近开发的场位错力学模型来补充多晶塑性的传统公式，该模型以机械严格的方式解释了可观察的极位错密度（在所需的分辨率范围内）的内应力和演化。 该理论应用于理解负载路径变化时的屈服这一重要的技术问题，从而能够对轧制金属产品的回弹和使用中应力松弛进行预测建模。该项目在提供一种低成本方法方面迈出了新的一步，可以分别针对任何装载和卸载路径方向的选择来预测产量和反向产量。结果将提供模拟能力，包括加工中的体晶体滑移、卸载中的非弹性以及最终产品的强度预测。 通过使用铝合金实现汽车轻量化仍然是减少温室气体排放和提高燃油效率的一种具有成本效益且及时的方法。这两个问题都对国家和国际经济和环境产生重大影响。了解冲压铝板的回弹和应力松弛对于设计用于生产汽车面板以实现轻量化的模具至关重要。该研究通过研究生教育增强了科学劳动力并丰富了教育材料。此项学术与工业联络的资助机会 (GOALI) 资助为卡内基梅隆大学和工业合作伙伴 ABAQUS, Inc 之间的联合研究工作提供了机会（罗德岛）。该项目以研究生建议的形式利用 ABAQUS, Inc. 的专业知识，并将我们的研究成果与商业 FEM 软件包 ABAQUS 进行集成。