Accession Number : AD0723210

Title :   On the Use of a Special Nonassociated Flow Rule for Problems of Elasto-Plastic Wave Propagation,

Corporate Author : WEIDLINGER (PAUL) NEW YORK

Personal Author(s) : Bleich,H. H.

Report Date : MAR 1971

Pagination or Media Count : 80

Abstract : Computational work to determine wave propagation in soils has been undertaken by various groups, using elasto-plastic materials with nonassociated flow rules. Theoretical objections against such computations have been raised, because in static problems nonassociated flow rules may lead to nonuniqueness of the solutions. For a typical example the situation is discussed by D. C. Drucker (Ref. 4). The present investigation demonstrates that the nonuniqueness shown in Ref. (4) disappears if the same material description is used in a dynamic problem. It is shown that the static behavior of a frequently used material subject to a Coulomb yield condition, but employing a von Mises plastic potential, exhibits again problems of uniqueness, but that these disappear in the dynamic situations studied. Uniqueness could be demonstrated not only in simple cases involving a homogeneous stress field, but also for the case of one dimensional wave propagation in a half-space subjected to combined surface pressure and surface shear. (Author)

Descriptors :   (*SOIL MECHANICS, MECHANICAL WAVES), (*MECHANICAL WAVES, EQUATIONS OF MOTION), ELASTIC PROPERTIES, PLASTIC PROPERTIES, STRESSES, STRAIN(MECHANICS), PRESSURE, LOADS(FORCES), BOUNDARY VALUE PROBLEMS

Subject Categories : Soil Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE