  Extreme localization of damage in conventional brittle materials is the
source of a host of undesirable effects. We show how artificially engineered
metamaterials with all brittle constituents can be designed to ensure that
every breakable sub-element fails independently. The main role in the proposed
design is played by high contrast composite sub-structure with zero-stiffness,
furnishing nonlocal stress redistribution. The ability to de-localize cracking
in such nominally brittle systems is revealed by the fact that their continuum
description is dominated by the gradient (bending) rather than classical
(stretching) elasticity. By engineering a crossover from brittle to effectively
ductile (quasi-brittle) behavior in prototypical systems of this type, we
reveal the structural underpinning behind the difference between fracture and
damage.
