Accession Number : ADA189000

Title :   Ultrasonic-Velocity Studies of Composite and Heterogeneous Materials,

Corporate Author : COLORADO UNIV AT BOULDER DEPT OF MECHANICAL ENGINEERING

Personal Author(s) : Datta, Subhendu K ; Ledbetter, Hassel M ; Shah, Arvind H

PDF Url : ADA189000

Report Date : Apr 1987

Pagination or Media Count : 29

Abstract : Ultrasonic measurements of wave-propagation characteristics in composite and heterogeneous materials provide an excellent means to study their mechanical properties. In recent years we have studied, both theoretically and experimentally, characteristics of elastic-wave propagation in particle-reinforced composites and heterogeneous materials as well as in homogeneous and laminated fiber-reinforced composites. Comparison of theoretical predictions with observations of wave velocities has shown good agreement and has provided a way to evaluate microstructural dependence of mechanical properties of these materials. Modeling predictions coupled with observations can also be used to obtain mechanical properties of the reinforcing phase, which are sometimes not easily obtained. In this paper we present results of some of these recent studies. We also present results of our study of changes in phase velocities and attenuation caused by interface layers between the reinforcing phase and the matrix. We show that this third phase measurably modifies the dispersion behavior. This should lead to effective characterization of interface layer properties by ultrasonic methods.

Descriptors :   *ELASTIC WAVES, *COMPOSITE MATERIALS, *WAVE PROPAGATION, COMPARISON, DISPERSING, FIBER REINFORCED COMPOSITES, HETEROGENEITY, HOMOGENEITY, INTERFACES, LAMINATES, LAYERS, MATERIALS, MEASUREMENT, MECHANICAL PROPERTIES, MICROSTRUCTURE, MODELS, PHASE, PREDICTIONS, REINFORCING MATERIALS, THEORY, ULTRASONICS, VELOCITY, ACOUSTIC ATTENUATION, ACOUSTIC VELOCITY, MODULUS OF ELASTICITY, DAMPING, ALUMINUM

Subject Categories : Laminates and Composite Materials
      Acoustics
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE