This facility allows material testing to be conducted for strain rates up to 106 s-1, under a range of multiaxial states of stress through normal and pressure-shear (inclined) plate impact experiments. The gas gun has an 80 mm diameter, 8 m long gun barrel connected to a 28.5 liter test chamber. A double diaphragm separates the test chamber and a large soft-recovery catcher tank. Impact velocities between 100 and 1200 m/s can be achieved and recorded. The large gun barrel diameter allows observations to be made under pure plane strain conditions for up to 15 ms. Controlled experiments are performed with impact planarities better than 50 milli-radians. The facility has state-of-the-art interferometric and stress-gauge diagnostic capabilities along with instrumentation for high-speed digital data acquisition. Time-resolved in-situ pressure measurements can be obtained using piezo-electric (PVDF) and piezo-resistive (Manganin) stress gauges. A VISAR (Velocity Interferometer System for Any Reflector) is available for free surface velocity measurements. This system is capable of making four simultaneous measurements with a sensitivity of 2 m/s and a depth of field of 12 mm. Velocities in the range of 30-50,000 m/s can be measured. Three four-channel Tektronix digital oscilloscopes (Model TDS784A) with a sampling rate of 4 Giga points per second are available for high-speed data acquisition with sub nanosecond resolutions.
Dr. Naresh Thadhani
Phone: 404-894-2651, Fax: 404-894-9140
Office: Room 154, MRDC-II (Manufacturing Related Disciplines Complex-II)