Implosion of a thin-walled cylinder of a viscoelastic material

The dynamic collapse of cylindrical shells is of interest for different applications including failure of pressure vessels, vascular collapse, and inertial confinement fusion. In this study, two materials of interest, hyperelastic elastomers and silicone oils, are prepared as thin-walled cylinders. The cylinders are imploded using shock waves in air at atmospheric conditions generated by a conventional shock tube and a novel, toroidal shock wave generator. Silicone elastomers with hyperelastic properties can be prepared as a liquid in a mold. Silicone oils are used as the fluid because they can be varied over several orders of magnitude of viscosity. Kinematic measurement of the implosion is acquired using high-speed videography and photonic Doppler velocimetry (PDV). The velocity of the inner surface of the cylindrical samples is recorded using PDV probes redirected via mirrors. Cylinders of different viscosities and geometries are imploded using various shock strengths to gauge the influence of material properties and sample geometries upon the dynamics of collapse. Results are interpreted using the concept of a critical velocity that derives from the viscosity of the material.