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过程中的内应力和松弛机制。研究方法是补充传统的多晶塑性配方与最近开发的场位错力学模型，占内部应力和可观察到的极性位错密度的演变（在所需的分辨率尺度）在机械上严格的方式。 该理论被应用到技术上的重要问题，了解屈服载荷路径变化，使预测模型的回弹和在服务中的应力松弛轧制金属产品。该项目提供了一个新的步骤，提供了一个低成本的手段，预测产量和反向产量的任何选择的装载和卸载路径方向，分别。其结果将提供一个模拟能力，包括体晶体滑移在处理中，非弹性卸载，并在最终产品的强度预测。 通过使用铝合金来减轻汽车重量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和及时的手段。这两个问题都对国家和国际经济及环境产生重大影响。了解冲压铝板的回弹和应力松弛对车身覆盖件的轻量化生产具有重要的指导意义。这项研究通过研究生的教育提高了科学劳动力，丰富了教育材料。这一赠款机会学术联络与产业（GOALI）赠款提供了一个机会，卡内基梅隆大学和工业合作伙伴，ABAQUS公司（罗得岛）之间的联合研究工作。该项目利用了ABAQUS，Inc.以研究生指导和将我们的研究成果与商业有限元软件包ABAQUS相结合的形式。