CAREER: All-Scale Continuum Models to Enable Load Path-Specific Material Design

该学院早期职业发展奖将支持多尺度力学方面的研究、教育和推广。预测塑性变形和失效对于能源、交通、国防和航天领域的无数技术的设计和安全运行至关重要。塑性和破坏同时受到原子级缺陷和结构级几何形状的影响。这种“天平专制”是力学领域的一个老大难问题。主要的研究目标是开发一种新的方法来有效地弥合这些规模。该方法显式地考虑了应变率和应力状态效应。该奖项将把这项研究纳入教育和推广经验。主要的教育目标是提高西班牙裔机械工程专业学生的6年毕业率。外展计划还将扩大K-12拉美裔学生参与STEM活动、教育和研究的范围。本研究项目旨在开发和演示一个全方位的连续统建模框架。其新奇之处在于它将连续介质建模有效而全面地扩展到原子尺度。该方法将表示和预测结构材料的全张量响应。该模型将根据一大套原子计算和实验进行校准和验证。这些数据集将跨越广泛的微观结构，例如，从位错匮乏到位错丰富的区域，以及广泛的应力状态和应变率。要研究的材料体系包括：(I)镁铝微柱；(Ii)纳米多孔金；(Iii)包覆的蜂窝纳米复合材料。这项研究通过更好地了解这三类材料和纳米结构在广泛的加载条件下的变形和破坏过程，为力学领域做出了贡献。该奖项将研究与教育相结合，开发一个基于游戏的学习平台。互动式教学工具将让学生对核心概念有更深入的理解和直观。选定的主题包括结构尺度的变形和破坏、原子尺度的变形和破坏、结构优化和材料设计。外展活动将通过“STEM亲朋好友之夜”面向中学生。这些年度活动将提供学习经验，并建立一个支持者、倡导者和倡导者网络，以加强各级参与STEM的渠道。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This Faculty Early Career Development (CAREER) award will support research, education, and outreach on multiscale mechanics. Predicting plastic deformation and failure is vital to the design and safe operation of countless technologies in the energy, transportation, defense, and space sectors. Plasticity and failure are simultaneously affected by atomic-scale defects and structure-scale geometry. This “tyranny of scales” is a long-standing problem in the field of mechanics. The primary research objective is to develop a new method to efficiently bridge these scales. The method explicitly accounts for strain-rate and stress-state effects. The award will integrate the research into educational and outreach experiences. The primary educational goal is to increase the 6-year graduation rate of Hispanic mechanical engineering students. The outreach plan will also broaden the participation of K-12 Hispanic students in STEM activities, education, and research.This research project seeks to develop and demonstrate an all-scale continuum modeling framework. The novelty lies in its efficient and comprehensive extension of continuum modeling down to atomistic-scales. The method will represent and predict the full tensorial response of structural materials. The model will be calibrated and validated against a large suite of atomistic calculations and experiments. These datasets will span a wide swath of microstructures, e.g., from dislocation-starved to dislocation-rich regimes, as well as a wide range of stress-states and strain-rates. The material systems to be studied include: (i) magnesium-aluminum micropillars; (ii) nanoporous gold; and (iii) coated cellular nanocomposites. The research contributes to the field of mechanics through a greater understanding of the deformation and failure processes of these three classes of materials and nano-structures across a broad range of loading conditions. This award integrates research with education to develop a game-based learning platform. The interactive teaching tool will give students a deeper understanding and intuition of core concepts. Selected topics include structural-scale deformation and failure, atomic-scale deformation and failure, structural optimization, and materials-by-design. Outreach activities will target middle school students through “STEM Family and Friend Nights.” These annual events will provide learning experiences and build a network of supporters, advocates, and champions that strengthen the pipeline of STEM participation at all levels.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.