Accession Number : AD0706894

Title :   DYNAMIC PLASTIC DEFORMATION OF METAL UNDER COMBINED STRESS STATES.

Descriptive Note : Final rept. 1 Dec 68-28 Feb 70,

Corporate Author : BROWN UNIV PROVIDENCE R I DIV OF ENGINEERING

Personal Author(s) : Duffey,J. ; Clifton,R. J.

Report Date : 1970

Pagination or Media Count : 6

Abstract : The objectives of the investigation was to obtain experimental information which would contribute to the understanding of the mechanisms involved in the dynamic plastic behavior of metals and which would aid in the development of constitutive equations applicable for plastic deformation at high rates of strain. The experimental program involved two essentially different, yet complementary, types of tests. In the first type of test a short tubular specimen was subjected to dynamic loading in combined tension and torsion for a period of time that was very long relative to the time required for stress wave propagation in the specimen. The objective of such a test was to obtain a dynamic stress-strain curve for straining along an essentially radial path in strain space. In the second type of test a long tubular specimen, initially pre-stressed in torsion, was subjected to a longitudinal impact. Because each of the plastic strain components (longitudinal and torsional) depends on both the normal stress and the shear stress, coupling between the longitudinal motion and the torsional motion occurs. As a result, combined longitudinal and torsional plastic waves are propagated. Study of this type of wave propagation provides insight into the form of the constitutive equations for dynamic plastic deformation under combined stress. (Author)

Descriptors :   (*LEAD ALLOYS, *DEFORMATION), RODS, LOADS(FORCES), STRESSES, STRAIN(MECHANICS), PLASTIC PROPERTIES, TEST METHODS

Subject Categories : Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE