Accession Number : AD0623958

Title :   LONGITUDINAL WAVE PROPAGATION IN AN ELASTICPLASTIC MEDIUM.

Descriptive Note : Technical rept.,

Corporate Author : LOCKHEED MISSILES AND SPACE CO SUNNYVALE CALIF

Personal Author(s) : Liu,D. T.

Report Date : SEP 1964

Pagination or Media Count : 75

Abstract : This report is concerned mainly with plane-wave propagation of large amplitude stresses in a medium where motion transverse to the direction of wave propagation is presented. Both the partial differential equations governing the stress-wave propagation and the jump conditions across a shock discontinuity are developed using the basic principles of the conservation of mass, momentum, and energy. The criterion for a stable shock front is discussed, and the wave structure arising, when the criterion is no longer satisfied, is described, The constitutive law is discussed in some detail with particular emphasis on the elastic-plastic behavior of ductile solids. The finite difference method is developed for solving onedimensional shock wave propagation problems with initial and boundary conditions prescribed in terms of pressure or velocity; i.e., arbitrary pressure pulse input, free surface, or an interface between two different media. The operational FORTRAN computer program is described in some detail. Capabilities include predicting the shock wave response, possible bond separation, and spallation failure in a multilayered medium composed of up to four different materials. Sample calculations which serve to illustrate the difference between the hydrodynamic and elastic-plastic behavior of solids under shock compression are also included. (Author)

Descriptors :   (*MECHANICAL WAVES, PROPAGATION), (*STRESSES, SOLIDS), ELASTIC PROPERTIES, PLASTIC PROPERTIES, ALUMINUM, STRUCTURES, LOADS(FORCES), DIFFERENTIAL GEOMETRY, EQUATIONS OF MOTION, COMPUTER PROGRAMMING

Subject Categories : Structural Engineering and Building Technology
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE