Review of experimental techniques for high rate deformation and shock studies

Cryogenic thermometry: a review of recent progress

The purpose of this review is to introduce the interested reader to the literature on the use of silica glasses in ballistic applications. These applications include optically transparent windows (where their amorphous nature, appropriate band gap, and cheapness make them ideal window materials) as well as layers in opaque armours designed to be resistant to shaped charges. In the latter application, their increase in volume (bulking) on fracture disrupts the shaped charge jet. Other topics covered in this review include low-velocity damage by windborne debris, liquid and solid impact, dynamic methods of testing (Hopkinson pressure bar, Taylor impact, and plate impact shock loading), and constitutive models. The use of glass as a shaped charge is also discussed.

An Introduction to the Properties of Silica Glass in Ballistic Applications

Commercial carbon composition resistors have been used as gauges to make dynamic stress measurements in homogeneous and heterogeneous reactive and inert materials. Initial loading was provided by plane wave lenses or shaped charge jets. A series of gas gun and aquarium experiments has been conducted to characterize the behavior of the gauges. Calibrations up to about 14 GPa for nominal 470 Ω resistors and 17 GPa for nominal 4700 Ω resistors are presented. The accuracy of the carbon resistor gauges is limited by response time considerations when submicrosecond rise times are encountered, and there is hysteresis during release. The gauge‐to‐gauge reproducibility appears to be adequate, and they survive in situations where no other stress transducer has been successfully used, such as in reacting beds of large‐particle gun propellants.

Commercial carbon composition resistors as dynamic stress gauges in difficult environments

This paper, a guide to the literature, is directed to experimentalists planning to extend their research into the temperature range of 0.01–1 K. Included are discussions of refrigeration, thermal contact and isolation, thermometry, and several examples of how standard physical measurement techniques have been adapted to the temperature regime below 1 K.

Instrumentation at temperatures below 1 K

A survey has been made of the properties of certain resistors (manufactured by the Allen‐Bradley Company) under hydrostatic pressure up to 11 kilobars at 295, 77, and 4.2 K. It is found that the resistance of the resistors (nominal value 220 Ω) decreases markedly with pressure and they may provide very sensitive pressure gauges. The reproducibility during a single pressure cycle is completely satisfactory, although the resistors show hysteresis effects when the pressure is removed.

R. L. White

Papers

Carbon Resistors as Pressure Gauges