An experimental model for solid fracture

A two-dimensional monodisperse dry liquid foam confined in a rectangular-channel Hele-Shaw cell driven by compressed air is used as a model system to study fracture and crack propagation in a solid. As a yield-stress material composed of mm-sized bubbles, the foam allows studies of failure at both the macroscopic (channel) and microscopic (bubble) scales. At smaller driving forces, a finger-like structure evolves emulating quasi-static crack growth. Higher driving forces cause fast rupture of consecutive films, drawing parallels with dynamic crack propagation.