Intensity of singular stress fields (ISSFs) in micro-bond test in comparison with ISSFs in pull-out test

Micro-bond test is often used to investigate fiber/matrix bonding behavior. In this experiment, the average shear stress is generally used as the interface strength without considering the singular stress. Therefore, in this paper, the intensity of singular stress field (ISSF) is newly analyzed at the fiber entry/exit points. The obtained ISSFs at the fiber entry point in micro-bond test are compared to the single fiber pull-out under the same fiber geometry. The results show that care should be taken for the previous micro-bond test geometry since the ISSF varies sensitively depending on the testing geometry. To control the initial fiber/matrix debonding and evaluate the bonding behavior correctly, suitable testing geometries are proposed in micro-bond testing.