Characterizing High-Strain-Rate Response of Cementitious Composites Using a Novel Strain-Energy-Based Impact Test System

使用新型应变能冲击测试系统表征水泥基复合材料的高应变率响应

• 批准号: 0754505
• 负责人: Sherif El-Tawil
• 金额: $ 25.09万
• 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: 2008
• 资助国家: 美国
• 起止时间: 2008-06-15 至 2012-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0754505&HistoricalAwards=false
• 关键词: Characterizing; Strain; Rate; Response; Cementitious

A novel test system is proposed for characterizing the high-strain-rate response of materials. The new method exploits the internal strain energy accumulated in an elastic bar to impart a high speed, high energy pulse onto a specimen. The proposed test system overcomes the combined limitations of traditional impact test setups and enables high quality impact testing in a scalable, cheap, compact, fast and safe manner. Another critical advantage is the ability to test with a small set-up, relatively large size specimens, which permits tests that more truly represent the behavior of non-homogenous building materials. Fundamental research will be conducted to optimize and explore the capabilities of the proposed system. The developed system will then be used to investigate the rate dependent behavior of high performance and ultra high performance fiber reinforced cementitious composites. These materials are known to possess exceptional strength, ductility and toughness under pseudo-static loading and therefore have the potential to serve as highly damage tolerant and energy absorbing materials under rapid loading conditions. The improvements in impact testing promised by the proposed technology will lead to faster de-velopment of better and more economical impact-resisting building materials. Enhancement in material response under high strain rate will eventually result in improvements in the ability of the national physical infrastructure system to better withstand unforeseen and extreme loading events. The work will also have an important impact on the development of human resources. Through the involvement of a diverse set of student researchers, a new generation of students will be introduced to the use of computational structural simulation, high strain rate testing, and high-performance structural materials.

提出了一种新的测试系统，用于表征材料的高应变率响应。新方法利用弹性杆中积累的内部应变能，向试样施加高速、高能脉冲。所提出的测试系统克服了传统冲击测试装置的综合限制，并以可扩展、廉价、紧凑、快速和安全的方式实现高质量的冲击测试。另一个关键的优势是能够用较小的装置、相对较大尺寸的试样进行测试，这允许测试更真实地代表非均质建筑材料的行为。将进行基础研究，以优化和探索拟议系统的能力。该系统将用于研究高性能和超高性能纤维增强水泥基复合材料的速率相关行为。已知这些材料在伪静态载荷下具有优异的强度、延展性和韧性，因此具有在快速载荷条件下用作高度损伤容限和能量吸收材料的潜力。所提出的技术在冲击测试方面的改进将导致更快地开发出更好、更经济的抗冲击建筑材料。提高材料在高应变率下的反应能力，最终将提高国家有形基础设施系统的能力，更好地承受无法预见的极端负荷事件。这项工作还将对人力资源开发产生重要影响。通过一组不同的学生研究人员的参与，新一代的学生将被引入到计算结构模拟，高应变率测试和高性能结构材料的使用。