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

粘弹性材料是一种应用广泛的材料，表征材料的力学行为和预测损伤扩展对于有效地使用这类材料是非常重要的。蠕变柔量和拉伸强度是粘弹性材料通常测量的性质;由于材料的固有速率依赖性，它们表示为时间或加载速率的函数。大多数粘弹性材料也依赖于温度;为了充分表征材料，必须在一定范围的加载速率和温度下进行测试。在实验室中有许多类型的测试用于测量粘弹性材料的行为。在这个时候，有没有办法链接或捆绑在一起的知识ofviscoelastic材料行为收集使用这些不同的测试geometrics.This教师早期职业发展（CAREER）的研究和教育提供了一种方法，开发本构之间的关系为基础的粘弹性材料性能测量使用各种测试几何形状。它将集中于开发轴向和间接拉伸测试，两个最广泛使用的测试方法之间的关系。还将评估三轴、梁弯曲和半圆弯曲方法。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，将用于捕获每个测试几何结构中感应的非均匀应变场。将对每种几何形状进行应力和应变场以及损伤增长模式的分析。拟议的教育和推广活动与研究计划有着内在的联系，以便：（1）有效地向评估粘弹性材料的政府机构、工业界和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）在工程学课堂上融入科技，培养探索的兴趣，以鼓励终身学习和支持研究活动;及（3）教育市民认识工程师在社会上的重要角色，吸引年青人投身工程专业。PI和学生将有机会在大众媒体以及技术会议上展示研究成果。在课堂上，重点将放在开发动手活动，让学生获得工程研究的感觉，同时测量和分析与拟议项目相关的实际测试数据。虚拟实验室等技术的整合和在线数据库的使用将是拟议活动的一个关键部分。一个研究小组的方法将实施包括本科生和研究生在一个重要的指导和研究经验。每个学生将有助于整体团队的努力，同时进行个人研究。将建立一个指导制度，以帮助建立和加强该小组的研究计划。将作出重大努力，从本科和研究生两级代表性不足的群体中招募学生，并将他们纳入研究团队。

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.