CAREER: Informed Testing — From Full-Field Characterization of Mechanically Graded Soft Materials to Student Equity in the Classroom

职业：知情测试 – 从机械分级软材料的全场表征到课堂上的学生公平

• 批准号: 2338371
• 负责人: Jonathan Estrada
• 金额: $ 76.31万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 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: 2024-03-01 至 2029-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2338371&HistoricalAwards=false
• 关键词: CAREER; Informed; Testing; Full; Field

Mechanical gradient soft materials (MGSMs) are compliant systems with smooth variations in their properties. MGSMs are observed in nature as stiff ligaments attaching seamlessly to bone, or hard shells or beaks on aquatic creatures. Recent advances in machine learning stand to customize the design of MGSMs for engineering purposes, ranging from soft robotics to impact absorption and biomedical devices. However, certifying that “what we planned is what we built” relies on our ability to peer into these materials and test their properties as they are stretched. This Faculty Early Career Development (CAREER) award supports fundamental research to establish a method which will both cause and quantify three-dimensional deformations inside designed soft materials. Informed testing will reduce the time it takes to determine how mechanical properties vary over a material, speeding up characterization efficiency and feedback loops for generally making personalized soft materials. This research will not only promote the progress of fundamental science but will also advance national health, prosperity, and welfare. By integrating informed testing into the engineering classroom, this research will additionally improve educational outcomes for—and broaden participation of—underrepresented groups. A single test procedure for reliably identifying spatial heterogeneity for materials undergoing large deformations has not yet been developed. Previously, magnetic resonance cartography had been used as a characterization method for soft materials without internal contrast, but the method is currently restricted to moderate deformations of homogeneous materials. This research aims to permit identification of spatial variations of material properties by using continuum mechanics theory and forward finite element simulations to inform experimental boundary conditions for tests. Furthermore, confidence in the identifiability these parameters will be assessed for the first time via an experimental goodness metric. The specific aims of the research are to (1) actuate and measure fully three-dimensional strain fields of MGSMs with peak strain magnitude values newly above 1, (2) assess the usefulness of deformation states using orthogonal strain invariants and the virtual fields method, and (3) determine how kinematic data richness and noise quantifiably alter the identifiability of the complete set of constitutive parameters of interest. The principles of informed testing will additionally be applied to driving assessment strategies in mechanics classrooms using course equity data and will underpin a personalized PrairieLearn-based mechanics mastery platform.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.

机械梯度软材料（MGSM）是符合性的系统，其性质的变化平稳。在自然界观察到MGSM，因为坚硬的韧带无缝地连接到骨骼上，或者在水生蛋白质上的硬壳或喙。机器学习的最新进展是定制用于工程目的的MGSM的设计，从软机器人技术到影响抽象和生物医学设备。但是，证明“我们计划的是我们建造的东西”取决于我们在伸展时凝视这些材料并测试其属性的能力。这项教师早期职业发展（职业）奖支持基本研究，以建立一种方法，该方法既会导致和量化设计的软材料内部的三维变形。知情测试将减少确定机械性能在材料上的变化所需的时间，从而加快表征效率和反馈回路，以制造个性化的软材料。这项研究不仅将促进基本科学的进步，而且还将促进国家健康，繁荣和福利。通过将知情的测试集成到工程课堂中，这项研究将进一步改善代表性群体的教育成果和扩大。尚未开发出一种可靠地识别经历大变形材料的空间异质性的单一测试程序。以前，磁共振制图已用作无内部对比度的软材料的表征方法，但是该方法目前仅限于均匀材料的现代化变形。这项研究旨在通过使用连续的机械理论和正向有限元模拟来识别材料特性的空间变化，从而为测试提供了实验边界条件。此外，将首次通过实验良好度量评估对识别的信心。该研究的具体目的是（1）具有峰值应变幅度值的实际和完全三维应变场，新近高于1，（2）评估使用正交菌株不变性和虚拟场方法的变形状态的有用性，以及（3）确定动力学数据丰富和噪声量化的兴趣量的概述的概念集的标识集合的构造集的概述。知情测试的原理还将用于使用课程权益数据来推动机械学教室中的评估策略，并将支持一个个性化的基于大草原的机械师掌握平台。该奖项反映了NSF的法定任务，并被认为是通过基金会的智力和更广泛的影响来通过评估来通过评估来获得支持的珍贵。