Accession Number : ADA300895

Title :   Parameterized Materials and Dynamic Response Characterizations in Unidirectional Composites.

Descriptive Note : Final contractor rept,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF MECHANICAL ENGINEERING

Personal Author(s) : Williams, James H., Jr. ; Marques, Elizabeth R.

PDF Url : ADA300895

Report Date : DEC 1986

Pagination or Media Count : 37

Abstract : The values 0f phase velocities of ultrasonic waves in transversely isotropic media are presented in terms of (a) the fiber volume fraction 0f a unidirectional fiberglass epoxy composite with constant matrix properties and (b) the ratio between extensional moduli in the longitudinal and transverse directions of the composite when the properties of the fibers are changed, at a constant fiber volume fraction. The model of a homogeneous transversely isotropic medium is adopted to describe the relations between elastic properties and velocities. The displacements due to an oscillatory point source in an infinite medium are used as one measure of comparison of the behavior of the unidirectional composite according to the variations of the parameters, as described above. Values of phase velocities, elastic moduli, Poisson's ratios and displacements due to a point source can be read from the parameterized plots for a known fiber volume fraction or a known ratio between extensional moduli of the composite.

Descriptors :   *FIBER REINFORCED COMPOSITES, *EPOXY COMPOSITES, FIBERGLASS, COMPOSITE MATERIALS, ACOUSTIC WAVES, DYNAMIC RESPONSE, STIFFNESS, DISPLACEMENT, ELASTIC PROPERTIES, MODULUS OF ELASTICITY, ULTRASONICS, OSCILLATION, POISSON RATIO, UNIDIRECTIONAL, PHASE VELOCITY.

Subject Categories : Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE