  A micropolar cohesive damage model for delamination of composites is
proposed. The main idea is to embed micropolarity, which brings an additional
layer of kinematics through the micro-rotation degrees of freedom within a
continuum model to account for the micro-structural effects during
delamination. The resulting cohesive model, describing the modified traction
separation law, includes micro-rotational jumps in addition to displacement
jumps across the interface. The incorporation of micro-rotation requires the
model to be supplemented with physically relevant material length scale
parameters, whose effects during delamination of modes I and II are brought
forth using numerical simulations appropriately supported by experimental
evidences.
