Fracture is often simulated using the cohesive zone model (CZM), which requires a traction-separation law (TSL) to govern crack growth. Molecular dynamics (MD) simulations can be used to determine the TSL between two materials, but this TSL considers very small length scales and defect-free conditions and so is typically very different from an experimentally determined TSL. Experimentally determined TSL for fiber-matrix interface debonding is the average behavior including the defects that may be present. We discuss a finite element modeling approach that takes an input TSL from MD calculations and introduces defects to investigate if the MD TSL with defects is equivalent to the experimental TSL. This approach links the defect-free MD length scale to the continuum scale with implications for materials-by-design.