Presidential Young Investigator Award: Micro-Mechanics of Fiber-Reinforced Composites

纤维增强复合材料的力学性能将在连续介质力学的框架内进行理论研究。重点将放在探索宏观特性的微观起源上，如硬度、强度和韧性。微观来源包括组成纤维和基质的性质、它们的几何形状以及它们彼此结合的程度。事实上，约束的程度将构成一个主要主题，许多拟议工作都围绕着这个主题展开。纤维-基质键的变化被认为对韧性有很大影响。特别是，在脆性基质系统中，键的降解经常导致韧性的增加。对这个问题的回答是，在不连续的纤维系统中，这种退化对硬度有什么影响？对于类似的问题，需要一种将键退化程度作为参数纳入相关力学问题的连续统分析的方法。将探索各种方法，并将研究一些关键问题，其中纤维-基质界面发挥重要作用。

The mechanical properties of fiber-reinforced composite materials will be studied theoretically within the framework of continuum mechanics. Emphasis will be placed on exploring the microscopic origins of macroscopic properties such as stiffness, strength, and toughness. Microscopic origins include the properties of the constituent fibers and matrix, their geometry, and the extent to which they are bonded to one another. In fact, the degree of bondedness will constitute a major theme around which much of the proposed work revolves. Alterations in the fiber-matrix bond have been thought to affect toughness significantly. In particular, degradation of the bond frequently leads to increased toughness in brittle matrix-systems. Response to the question, What effect does such degradation have on stiffness in, say, discontinuous fiber systems? and to similar questions requires a means of incorporating the degree of bond degradation as a parameter into continuum-analyses of relevant mechanics problems. Various means will be explored, and a number of key problems in which the fiber-matrix interface plays a significant role will be studied.