Cracks in rubber under tension exceed the shear wave speed

TL;DR

This paper demonstrates that in non-linear rubber, tension cracks can travel faster than shear wave speed, reaching intersonic velocities between shear and longitudinal wave speeds, challenging previous assumptions.

Contribution

It reveals that non-linear materials like rubber can host cracks exceeding shear wave speed, a phenomenon not observed in linear elastic solids.

Findings

Cracks in rubber can exceed shear wave speed in tension.

Intersonic crack speeds are achievable in highly stretched rubber.

Simple balloon popping can generate intersonic cracks.

Abstract

The shear wave speed is an upper limit for the speed of cracks loaded in tension in linear elastic solids. We have discovered that in a non-linear material, cracks in tension (Mode I) exceed this sound speed, and travel in an intersonic range between shear and longitudinal wave speeds. The experiments are conducted in highly stretched sheets of rubber; intersonic cracks can be produced simply by popping a balloon.