Accession Number : ADA194710

Title :   Lagrangian Analysis.

Descriptive Note : Technical rept. 1 Dec 86-1 Mar 87,

Corporate Author : CALIFORNIA RESEARCH AND TECHNOLOGY INC ALBUQUERQUE NM

Personal Author(s) : Lloyd, George M ; Rinehart, Eric J

PDF Url : ADA194710

Report Date : 01 Mar 1987

Pagination or Media Count : 60

Abstract : Estimation of stress and strain paths followed in in situ, high explosive field tests may be obtained from direct inversion of the velocity and stress histories measured. When the field tests are designed as one-dimensional tests (planar, cylindrical, or spherical), a technique commonly called Lagrangian Analysis of Stress and Strain (LASS) has been employed. The results from recent LASS analysis of dry soils have not been self-consistent nor yielded estimates which have been shown to be better than currently arrived at by lab tests and parametric calculations. This report develops another method of LASS which deviates somewhat from earlier path line and traveling wave formulations. Equations for the new method are derived. Estimates due to instrumentation inaccuracy are examined. Methodological errors in estimation of strains and stress bounds are also investigated. While this paper does not address all the possible sources of inconsistency, it will point out many which have not received attention before. Specifically, errors due to instrumentation inaccuracy; and methodological errors in estimation of strains and stress bounds. Keywords: Material models; Lagrangian analysis; Constitutive relationships.

Descriptors :   *LAGRANGIAN FUNCTIONS, *TEST METHODS, *MATHEMATICAL ANALYSIS, *STRESS STRAIN RELATIONS, ACCURACY, COMPUTATIONS, DRY MATERIALS, EQUATIONS, ERRORS, ESTIMATES, FIELD TESTS, FORMULATIONS, INSTRUMENTATION, INVERSION, LABORATORY TESTS, METHODOLOGY, PARAMETRIC ANALYSIS, PATHS, SOILS, STRESSES, TRAVELING WAVES, ALGORITHMS, MATHEMATICAL MODELS

Subject Categories : Ammunition and Explosives
      Numerical Mathematics

Distribution Statement : APPROVED FOR PUBLIC RELEASE