A set of multi-scale materials systems design tools focused on issues relevant to self-healing structural composites have been developed by a research team from the University of Illinois and the University of Michigan. Our vision was to create a computational framework for materials systems design spanning from atomistic to macroscopic (structural) length scales, supported and validated by a set of experiments conducted at various scales. Although special emphasis in the present project ha been placed on the modeling of the fatigue response of a self-healing composite, the approach adopted in this project yielded tool that have broad applicability for generic fracture and fatigue problems in modem engineering materials. This paper summarizes our accomplishments of the past three years primarily on the macroscale numerical and experimental aspects of the program. 0 the numerical side, we have focused on the development, implementation and validation of a cohesive failure model able to capture at the structural level the fatigue retardation effect of the healing agent on the cyclic response of the self-healing composite.