  Advances in the field of topological mechanics have highlighted a number of
special mechanical properties of Maxwell lattices, including the ability to
focus zero-energy floppy modes and states of self-stress (SSS) at their edges
and interfaces. Due to their topological character, these phenomena are
protected against perturbations in the lattice geometry and material
properties, which makes them robust against the emergence of structural
non-idealities, defects, and damage. Recent computational work has shown that
the ability of Maxwell lattices to focus stress along prescribed SSS domain
walls can be harnessed for the purpose of protecting other regions in the bulk
of the lattice from detrimental stress concentration and, potentially,
inhibiting the onset of fracture mechanisms at stress hot spots such as holes
and cracks. This property provides a powerful, geometry-based tool for the
design of lattice configurations that are robust against damage and fracture.
In this work, we provide a comprehensive experiment-driven exploration of this
idea in the context of realistic structural lattices characterized by
non-ideal, finite-thickness hinges. Our experiments document the onset of
pronounced domain wall stress focusing, indicating a remarkable robustness of
the polarization even in the presence of the dilutive effects of the structural
hinges. We also demonstrate that the polarization protects the lattice against
potential failure from defected hinges and cracks in the bulk. Finally, we
illustrate numerically the superiority of SSS domain walls compared to other
trivial forms of reinforcements.
