Accession Number : AD0908557

Title :   Pulse Propagation in Straight Circular Elastic Tubes.

Descriptive Note : Technical publication Jun 70-May 71,

Corporate Author : NAVAL WEAPONS CENTER CHINA LAKE CA

Personal Author(s) : Goldsmith, W. ; Lee, P. Y. ; Sackman, J. L.

Report Date : MAR 1973

Pagination or Media Count : 19

Abstract : An experimental investigation of elastic waves produced by the longitudinal impact of strikers with straight 2024 aluminum tubes of 1-in. dia and wall thickness of 0.035 in. (thin walled), 0.095 in. (medium thick-walled), and 0.5 in. (solid bar) was performed by means of the Hopkinson bar technique. For most of the tests the strikers consisted of 1/2-in-dia steel balls; however, 1/4-in-dia, 3/16-in-dia and 1/8-dia steel balls were also used to permit variation in pulse duration. Both central and eccentric impact were achieved by firing the striker from an air gun at a predetermined pressure against the carefully positioned target; the initial velocity of the striker was measured whenever necessary. Longitudinal strain records of the resulting pulse from positions both on the inside and outside surfaces of the hollow specimens and on the outside of the solid bar were obtained by using strain gages of either foil or semiconductor type; some transverse strain histories were also measured concurrently. The transient longitudinal strains were predicted theoretically by solving the one-dimensional Rayleigh-Love equation of wave propagation in a semi-infinite tube with the aid of a computer program. The input to the program consisted of the measured strain record at the first gage station. Reasonable agreement between the data and the results of these calculations was obtained. An experimental investigation of the effect of shortening the pulse duration, the relation between the transverse and longitudinal strain at the same position, and the nature of the antisymmetrical component in the eccentric shots was also undertaken. (Author)

Descriptors :   (*MECHANICAL WAVES, PIPES), HARMONIC ANALYSIS, WAVE PROPAGATION, WALLS, THICKNESS, STRAIN(MECHANICS), COMPUTER PROGRAMS, PULSES, RODS, INTERIOR BALLISTICS, GUN BARRELS, RAYLEIGH WAVES, MATHEMATICAL ANALYSIS.

Subject Categories : Radiofrequency Wave Propagation

Distribution Statement : APPROVED FOR PUBLIC RELEASE