Fracture of the Aluminum Sheath of a Thick-Walled Composite Cylinder by Electrical Explosion of a Conductor

Experimental data for the destruction of an aluminum sheath covering a press-fitted PMMA cylinder are reported. A copper conductor to be exploded is inserted into the cylinder along its axis, and a voltage is applied to the conductor from a capacitor charged to 20–22 kV. An explosion-induced pressure is transferred by a blast shock wave to PMMA and then to the metallic sheath. As a result, the PMMA cylinder breaks down and the aluminum sheath ruptures. The amplitude of the explosion-induced pressure, which is transferred to the PMMA cylinder and then from the cylinder to the sheath, has been estimated by measuring radial pressures, and sheath rupture stresses have been determined. The microstructure of the ruptured aluminum sheath has been examined using a Tescan scanning electron microscope and a Discovery optical stereomicroscope.