Effects of interfacial debonding and fiber breakage on static and dynamic buckling of fibers in matrices.

Abstract

Analyses were performed for static and dynamic buckling of a continuous fiber embedded in a matrix and fiber breakage in order to determine the effects of interfacial debonding on the critical buckling load and the domain of instability. A beam on elastic foundation model was used for this study. The study showed that a local interfacial debonding between a fiber and a surrounding matrix resulted in an increase of the wavelength of the buckling mode. An increase of the wavelength yielded a decrease of the static buckling load and lowered the dynamic instability domain. In general, the effect of a partial or complate interfacial debonding was more significiant on the domain of dynamic instability than on the effects of static buckling load. For dynamic buckling of a fiber, a local debonding of size 10 to 20 percent of the fiber length had the most important influence on the domains of dynamic instability regardless of the location of debonding and the boundary conditions of the fiber. For static buckling, the location of a local debonding waa critical to a free-simply supported fiber but not to a fiber with both ends simply supported. Fiber breakage also lowered the critical buckling load significantly.