Role of Gradient and Multiscale Interface Morphology in Three- Dimensional Reinforcements in Composites (Preprint)

摘要

The interface morphology tailoring between the constituent phases in composites (e.g., fiber-matrix, inter-lamina, inter-yarn, nano-constituents- matrix, etc.) is essential in optimizing composite properties. In the case of composite strength, the mismatch of properties between the phases causes stress concentration at the interfaces, which in turn causes the initiation of damage and failure. A way of minimizing the mismatch of properties at the interface is demonstrated to reduce the interface stress concentration and hence delay the damage initiation process together with improving composite strength. Further, controlling the interface impedance mismatch is also important in controlling scattering of thermal energy at the interface to tailor thermal conductivity of composites, especially in the thickness direction. A gradient interface material morphology is thus desirable to enhance strength as well as other properties (e.g., thermal) of composites. Incorporation of nano constituents in composites now potentially enable us to implement the gradient interface morphology at multiple scale level, from nano meter (nano constituent interface) to laminate ply interlayer (micro meter scale). In this study, the effect of implementing the gradient interface at different scale level is reviewed to assess its potential in enhancing composite strength and thermal properties.