Micromechanics of fiber–crack interaction studied by micro-Raman spectroscopy: Bridging fiber

Micromechanics of bridging fiber/crack interaction were investigated by micro-Raman spectroscopy. The stress distribution on a bridging fiber was measured point-by-point using micro-Raman spectroscopy. The interaction between the crack and bridging fiber was discussed and a bridging fiber stress transfer model was established. A reverse sliding of the bridging fiber within the debonded zone was gradually converted to a forward sliding during reloading and at last the bridging fiber was wholly reloaded. It is noted that the stress on the bridging fiber distributed uniformly and a fiber bridging zone is isolated from the fiber debonded zone in the new model. The interfacial friction does not work within the bridging fiber length so that the bridging fiber stress remains a constant.

► A stress transfer model is proposed to describe friction sliding mechanism for bridging fiber.
► Reverse sliding gradually transforms into forward sliding as the bridging fiber is reloading.
► Uniform stress exists in the bridging fiber.