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.

从理论上讲，具有负泊松比（即辅助物质）的材料提高了硬度，抗抗性，断裂韧性和剪切模量，而剪切模量则具有阳性泊松比和同一年轻人的模量。据报道，在随机纤维结构中辅助行为的实验证据已报道，但是这类辅助材料在很大程度上仍在探索中。 在这里，将使用数值和实验方法研究辅助纤维增强复合材料的设计和开发的替代途径。中心假设是可以通过将辅助纤维网络嵌入常规矩阵材料中来制造辅助复合材料。 该假设的有效性将通过复合样品的制造和机械测试在项目的实验组成部分中进行研究。 主要的建模目标是开发数值网络模型，从而可以彻底研究随机纤维网络材料的辅助行为。 智力优点在于通过探索设计辅助材料的替代路线来获得的好处。 数值模型将是辅助材料领域中的有价值工具，对于新的复合材料的设计和开发至关重要，这些材料均针对Young的模量和Poisson比率进行了优化。 来自代表性不足小组的K-12学生的外展活动将通过提高对工程学的认识和兴趣来对项目产生更广泛的影响，并使学生有机会通过校园访问，演讲和指导活动来了解研究活动。