Abstract
A simple Dagdale model for fiber bridging processes and mechanisms of unidirectionally fiber-reinforced brittle matrix composites is addressed. The model, the most primitive and the simplest one, has great advantages in analytical solutions and practical considerations, although it is not enough for quantitatively explaining experimental results. It is emphasized that the details of crack-face constitutive relation (crack bridging tractions vs. crack opening displacement relationship) are not essential for describing the toughness increment of fiber bridging systems, but that the averaged bridging traction and the bridging zone length are the most important in the considerations of crack-bridge toughening.
