Micromechanics of Interfacial Failure in Composites

本研究的目标是建立纤维增强复合材料试件的宏观性能(强度和韧性)与微观尺度上纤维-基体界面的可观测和可测量性能之间的关系。提出的微观、中观和宏观三种尺度模型的第一步是基于实验测量的界面表面的标度不变(分形)表示。接下来，在实际接触的粗糙表面上确定所有的互锁力、粘附力和毛细作用力。这些预测得到了实验的证实。一旦确定了表面(对应于特定材料和特定加工)的统计数据和接触点上的接触力，就有必要研究该系统的强度和稳定性。应用渗流理论和自组织临界性确定了脱粘和/或摩擦滑移的开始。该计划的所有阶段都将是相互一致的。基本物理现象的几何学和物理学将被严格对待。

The objective of this research program is to establish the relationship between the observable and measurable properties of the fiber-matrix interfacial surface on the micro-scale and the macro-properties (strength and toughness) of a fiber reinforced composite specimen. The first step in the development of the proposed three (micro, meso and macro) scale model consists of a scale invariant (fractal) representation of the interfacial surface based on experimental measurements. Next, all interlock, adhesive and capillary forces are determined on the asperities in actual contact. These predictions are corroborated by experiments. Once the statistics of the surface (corresponding to particular materials and specific processing) and contact forces on the contact spots are determined it becomes necessary to study the strength and stability of that system. The onset of debonding and/or frictional slip is determined applying the percolation theory and self-organizing criticality. All phases of this program will be mutually consistent. Geometry and physics of the underlying physical phenomena will be rigorously treated.