Damage propagation in lattice structures*

In this work we investigate the fracture propagation in a two-dimensional (2D) Maxwell lattice. In general, elastic brittle material will fail catastrophically due to stress concentrations at the crack tip. Maxwell lattices are on the verge of mechanical stability and these properties can be leveraged to control the crack propagation through the lattice and provide protection from defects. We present the principles that enable the control of the fracture in a kagome lattice and illustrate, through numerical simulations, how these principles can be applied to architect the fracture through the lattice. Numerically the lattice is represented as a series of sites connected by harmonic springs with elastic brittle material response. Ultimately we show that these principles can be used to control the crack and therefore the fracture toughness of the lattice.