This study used 2-D axisymmetric finite element model to simulate propagating a penny-shaped crack in a brittle fiber under constant longitudinal tensile load. The finite element analysis was divided into three separate parts. Each part investigated the influence of a single criterion on the possibility of fiber-matrix interface failure due to the perpendicularly impinging fiber crack on the interface. The three criteria were: fiber-volume fraction, fiber orthotropy, and thermal load.
- The interface tensile failure is more likely to occur when both the fiber-volume fraction and fiber-to-matrix modulus ratio are high.
- The interface in the silicon carbide/epoxy will not fail in shear regardless of the fiber volume fraction.
- In the early and middle stages of crack growth, the presence of orthotropic fiber in the graphite/epoxy composite increases the likelihood of tensile interface failure with increasing fiber-volume fraction.
- The fiber orthotropy in the graphite/epoxy composite diminishes the likelihood of interface failure in shear.
- The presence of thermal stress in the graphite/epoxy composite lowers the possibility of interface failure in tension and in shear.