Accession Number : ADA304036

Title :   Formulas for the Pressure and Bulk Modulus in Uniaxial Strain.

Descriptive Note : Final rept. May-Jul 95,

Corporate Author : ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD

Personal Author(s) : Scheidler, Michael J.

PDF Url : ADA304036

Report Date : FEB 1996

Pagination or Media Count : 18

Abstract : For an isotropic elastic solid, the Pressure P = Pu(P) in a state of uniaxial strain at density p generally differs from the pressure P = Ph(p) in a state of hydrostatic stress at the same density. Several researchers have used pressure/shear (or oblique plate impact) tests to determine Pu and the corresponding uniaxial bulk modulus Ku is equivalent to pdPu/dp. The pressur/shear tests yield uniaxial longitudinal and shear moduli, Lu and Gu, as functions of p. A common procedure is to integrate the approximate relation Ku approx. = Lu - 4/3Gu to obtain the pressure-density relation P = Pu(P) in uaiaxial strain. It is shown here that the integration of this approximate relation between the moduli can be avoided altogether by utilizing the exact formula Pu = a1 - 2/3((p/po)2 - 1)Gu, where a1 denotes the longitudinal stress (positive in comPression). The bulk modulus Ku is computed exactly from this formula, and the wor in approximating it by Lu - 4/3Gu is determined. (AN)

Descriptors :   *STRESS ANALYSIS, *AXIAL LOADS, *BULK MODULUS, STRESS STRAIN RELATIONS, DENSITY, ACCELERATION, IMPACT TESTS, DEFORMATION, SHEAR MODULUS, SHOCK WAVES, PRESSURE MEASUREMENT, APPROXIMATION(MATHEMATICS), SHEAR STRESSES, HYDROSTATIC PRESSURE, THERMOELASTICITY.

Subject Categories : Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE