Toward Negative Poisson's Ratio Composites - Numerical and Experimental Study

走向负泊松比复合材料 - 数值和实验研究

• 批准号: 0728109
• 负责人: Lesley Berhan
• 金额: --
• 依托单位: University of Toledo
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-06-15 至 2011-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0728109&HistoricalAwards=false
• 关键词: Toward; Negative; Poisson; Ratio; Composites

In theory a material with a negative Poisson's ratio (i.e. an auxetic material) has improved hardness, impact resistance, fracture toughness, and shear modulus over one with a positive Poisson's ratio and the same Young's modulus. Experimental evidence of auxetic behavior in random fibrous architectures has been reported, but this class of auxetic materials remains largely under explored. Here an alternate route to the design and development of auxetic fiber reinforced composites will be investigated using numerical and experimental methods. The central hypothesis is that an auxetic composite can be manufactured by embedding an auxetic fibrous network within a conventional matrix material. The validity of this hypothesis will be investigated in the experimental component of the project through the fabrication and mechanical testing of composite samples. The primary modeling objective is the development of a numerical network model whereby the auxetic behavior of random fibrous network materials can be thoroughly investigated. The intellectual merits lie in the benefits to be gained by exploring alternate routes to the design of auxetic materials. The numerical model will be a valuable tool in the field of auxetics and will be critical to the design and development of new composite materials which are optimized for both Young's modulus and Poisson ratio. The outreach activities to K-12 students from underrepresented groups will serve to provide a broader impact of the project through increased awareness and interest in engineering and give students the opportunity to learn about the research activities through campus visits, presentations and mentoring activities.

理论上，具有负泊松比的材料（即拉胀材料）比具有正泊松比和相同杨氏模量的材料具有更高的硬度、抗冲击性、断裂韧性和剪切模量。随机纤维结构中拉胀行为的实验证据已被报道，但这类拉胀材料仍处于很大程度上探索之中。 在这里，将使用数值和实验方法研究拉胀纤维增强复合材料的设计和开发的替代途径。中心假设是拉胀复合材料可以通过将拉胀纤维网络嵌入传统基质材料中来制造。 该假设的有效性将在该项目的实验部分通过复合材料样品的制造和机械测试进行研究。 主要建模目标是开发数值网络模型，通过该模型可以彻底研究随机纤维网络材料的拉胀行为。 智力上的优点在于通过探索拉胀材料设计的替代途径可以获得的好处。 该数值模型将成为拉胀领域的一个有价值的工具，并且对于针对杨氏模量和泊松比进行优化的新型复合材料的设计和开发至关重要。 针对来自代表性不足群体的 K-12 学生的外展活动将通过提高对工程的认识和兴趣来提供更广泛的项目影响，并让学生有机会通过校园参观、演示和指导活动了解研究活动。