The Impact Tube: A New Experimental Technique for Applying Impulse Loads
SourceThis paper is concerned with the development of a new experimental technique for applying loads of an impulsive nature to diaphragms or plates of various shapes. Briefly, this technique utilizes an adaptation of the shock tube principle which has been used successfully in the investigation of various supersonic aerodynamic problems. By rupturing a diaphragm which separates a high- and a low-pressure chamber, an expansion wave is created which travels toward the opposite wall of the high-pressure chamber containing the specimen under investigation. Behind the specimen is another high-pressure chamber. As the wave impinges on the specimen, a pressure differential between the second chamber and the pressure wave is applied to the specimen in an impulsive manner. This technique can be used to study the dynamic response of plates or the strength characteristics of membranes. Considerations involved in the design of the various components of the impact tube are discussed in detail. The results of an exploratory program on the dynamic pressure-strain relations in the yield region are presented for aluminum alloy 2S-O, annealed type 302 stainless steel, and annealed low-carbon steel.