  Kirigami are part of the larger class of mechanical metamaterials, which
exhibit exotic properties. This article focuses on rhombi-slits, which is a
specific type of kirigami. A nonlinear kinematic model was previously proposed
as a second order divergence-form PDE with a possibly degenerate, and
sign-changing coefficient matrix. We first propose to study the existence of
solutions to a regularization of this equation by using the limiting absorption
principle. Then, we propose a finite element method with complex polynomials to
approximate the solutions to the nonlinear equation. Finally, simulations are
compared with experimental results.
