Acoustic emission charaterization of singel and dual fiber reinforced metal matrix composites

摘要

Interfacial shear strength (IFSS) between fiber and matrix is one of the most important factors in characterizing the mechanical properties of fiber rinforced composites. If the IFSS is too low, it's hard to expect the performance of reinforcing fibers in composites, whereas if the IFSS is too high, there is a decrease in fracture toughness of composites because of the poor resistance to the stres crack propagation. Hence, it is necessary that the IFSS should be determined via the optimization rather than the maximization for the purpose. Several micro-mechanical techniques were proposed for measuring IFSS in composites. Some of the most frequently used techniques include the single fiber pull-out test[1], the single fiber composite (SFC) test[2], and micro-indentaton method[3]. Among them, the SFC test, originally proposed by Kelly and Tyson[4], has recived a lot of attention both as a diagnositc for fiber/matrix adhesion and as a simple composite system composed of the elastic fiber imbedded in a plastic matrix, Kelly and Tyson showed that the critical fragment length, is given.