Accession Number : AD0718087

Title :   Wave Propagation in a Composite Material Containing Dispersed Rigid Spherical Inclusions,

Corporate Author : RAND CORP SANTA MONICA CALIF

Personal Author(s) : Moon,F. C. ; Mow,C. C.

Report Date : DEC 1970

Pagination or Media Count : 33

Abstract : A dynamic model is presented concerning the effects of stress waves on composite materials with rigid spheres in an elastic matrix, such as plastics with small particle fillers to increase stiffness and sound absorption, or metal solutions that separate during solidification into, say, steel-carbide spheroids in a ferrite matrix. In a dilute suspension with randomly distributed particles, multiple interactions between inclusions can be neglected; and the dispersion and attenuation of waves in the medium can be found in terms of the local scattering processes at each inclusion. Coupled equations of motion for both matrix and inclusions were derived through a variational technique. Results show the well-known fourth-power dependence of attenuation on frequency. As the dynamics of wave scattering introduce inertia affects not explained by the mass and diameter of the inclusions alone, a constitutive equation involving the velocities must be specified. (Author)

Descriptors :   (*COMPOSITE MATERIALS, MECHANICAL WAVES), (*AEROSPACE CRAFT, AERODYNAMIC LOADING), SCATTERING, VIBRATION, HARMONIC ANALYSIS, STRESSES, ELASTIC PROPERTIES, EQUATIONS OF MOTION, REENTRY VEHICLES

Subject Categories : Laminates and Composite Materials
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE