Accession Number : AD0802089

Title :   ULTRASONIC STUDIES OF THE NONLINEAR PROPERTIES AND OF THE DEFORMATION OF SOLIDS. PART II.

Descriptive Note : Final rept., 1 Jan-31 Dec 65,

Corporate Author : BROWN UNIV PROVIDENCE RI METALS RESEARCH LAB

Personal Author(s) : Hikata, Akira ; Sewell, Frank A., Jr. ; Chick, Bruce B. ; Elbaum, Charles

Report Date : JUN 1966

Pagination or Media Count : 72

Abstract : The report covers research on the nonlinear properties of solids, with special emphasis on the role of dislocations in harmonic generation, the effects of plastic deformation and dislocation interactions with point defects. Dislocation breakaway from pinning points was considered as a possible source of harmonic generation; this contribution is of the same sign as that from screw dislocations. Experiments were carried out on aluminum single crystals with several different impurity contents, as measured by electrical resistivity ratios R(300 K)/R(4.2 K) ranging from 270 to 3100. Amplitudes of the third harmonic, as well as the attenuation of the fundamental wave, were measured as a function of bias stress, amplitude of the fundamental wave and amount of plastic deformation. The results of these experiments are consistent with the qualitative predictions of the theory presented.

Descriptors :   (*SINGLE CRYSTALS, DEFORMATION), SOLIDS, EQUATIONS OF MOTION, HARMONIC ANALYSIS, NUMERICAL ANALYSIS, MECHANICAL WAVES, DISTORTION, ULTRASONIC RADIATION, ULTRAHIGH FREQUENCY, ALUMINUM, PLASTIC PROPERTIES, CRYSTAL DEFECTS, VIBRATION, STRESSES, DAMPING, PARTIAL DIFFERENTIAL EQUATIONS, ATTENUATION, IMPURITIES, MODULATION, EXPERIMENTAL DATA.

Subject Categories : Crystallography
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE