CAREER: Relating Fundamental Viscoelastic Material Properties and Strengths Measured Using Various Testing Geometries

职业：关联使用各种测试几何形状测量的基本粘弹性材料属性和强度

• 批准号: 0348249
• 负责人: Jo Sias
• 金额: $ 40.07万
• 依托单位: University of New Hampshire
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2010-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0348249&HistoricalAwards=false
• 关键词: CAREER; Relating; Fundamental; Viscoelastic; Material

AbstractViscoelastic materials are widely used and characterizing the material behavior and predicting damage growth are very important for effective use of these materials. The creep compliance and tensile strength are properties that are commonly measured for viscoelastic materials; they are expressed as a function of time or rate of loading because of the inherent rate dependency of the material. Most viscoelastic materials are also temperature dependent; to fully characterize the material, testing must be performed at a range of loading rates and temperatures. There are numerous types of tests that are used in the laboratory to measure viscoelastic material behavior. At this time, there is no way to link or tie together the knowledge ofviscoelastic material behavior gathered using these different test geometries.This Faculty Early Career Development (CAREER) research and education offers an approach todeveloping constitutive based relationships between the viscoelastic material properties measured using various test geometries. It will focus on developing a relationship between axial and indirect tension testing, two of the most widely used test methods. The triaxial, beam bending, and semi-circular bending methods will also be evaluated. The digital image correlation (DIC) method, a non-contact technique for measuring full field displacements, will be used to capture the non-uniform strain fields that are induced in each of the test geometries. Analysis of the stress and strain fields and damage growth patterns will be performed on each of the geometries.The proposed educational and outreach activities are intrinsically linked to the research plan to: (1) effectively disseminate research results to government agencies, industries, and researchers that evaluate viscoelastic materials as well as the general public that depend upon the performance of these materials; (2) integrate technology and foster the excitement of discovery in the engineering classroom to encourage lifelong learning and support research activities; and (3) educate the general public on the important roles engineers play in society and attract young people to the engineering profession. Opportunities for the PI and students to present research results in mass media outlets as well as technical meetings will be explored. In the classroom, emphasis will be placed on developing hands-on activities that allow the students to get a feel for engineering research while measuring and analyzing actual test data related to the proposed project. The integration of technology such as virtual laboratories and use of online databases will be a key part of the proposed activities. A research team approach will be implemented to include both undergraduate and graduate students in a significant mentoring and research experience. Every student will contribute to the overall team effort while conducting individual research. A system of mentoring will be established to help build and enhance the team's research program. A significant effort will be made to recruit students from underrepresented groups at both the undergraduate and graduate levels and incorporate them into the research team.

摘要粘弹性材料是一种应用广泛的材料，表征材料的行为和预测损伤扩展对于有效利用这些材料是非常重要的。蠕变柔量和拉伸强度是粘弹性材料通常测量的特性；由于材料固有的速率依赖性，它们被表示为时间或加载速率的函数。大多数粘弹性材料也与温度有关；为了充分表征材料的特性，必须在一定的加载速率和温度范围内进行测试。实验室中有许多类型的测试用于测量粘弹性材料的行为。目前，没有办法将使用这些不同的测试几何收集的粘弹性材料行为的知识联系或联系在一起。这项学院早期职业发展(职业生涯)研究和教育提供了一种方法，可以在使用各种测试几何测量的粘弹性材料属性之间建立基于本构关系的关系。它将专注于发展轴向拉伸试验和间接拉伸试验之间的关系，这两种试验方法是最广泛使用的。还将评估三轴弯曲、梁弯曲和半圆形弯曲方法。数字图像相关(DIC)方法是一种用于测量全场位移的非接触式技术，将用于捕获在每个测试几何形状中诱导的非均匀应变场。拟议的教育和推广活动与研究计划有内在的联系：(1)有效地向政府机构、行业和评估粘弹性材料的研究人员以及依赖这些材料性能的普通公众传播研究成果；(2)整合技术并在工程课堂上培养发现的兴奋感，以鼓励终身学习和支持研究活动；以及(3)教育公众了解工程师在社会中所扮演的重要角色，并吸引年轻人加入工程专业。将探索为国际和平研究所和学生提供在大众媒体和技术会议上展示研究成果的机会。在课堂上，重点是开展实践活动，让学生在测量和分析与拟议项目相关的实际测试数据的同时，对工程研究有一种感觉。整合虚拟实验室等技术和使用在线数据库将是拟议活动的一个关键部分。将实施研究小组方法，将本科生和研究生纳入重要的指导和研究经验。每个学生都将在进行个人研究的同时，为整个团队的努力做出贡献。将建立一个指导系统，以帮助建立和加强团队的研究计划。将作出重大努力，从本科生和研究生中代表性不足的群体中招收学生，并将他们纳入研究小组。