Accession Number:

ADA183390

Title:

Thermal Expansion of Composites with Spherical and Cylindrical Inclusions.

Descriptive Note:

Final rept.,

Corporate Author:

NAVAL RESEARCH LAB WASHINGTON DC

Personal Author(s):

• Klemens,Paul G.

Report Date:

1987-07-21

Pagination or Media Count:

18.0

Abstract:

The strain field about a spherical inclusion consists of a uniform dilation and a short-range field which has pure shear character. By minimizing the strain energy, these fields are expressed in terms of the misfit of the inclusion. For a finite concentration of inclusions, the average properties of the material are used in place of those of the matrix. The thermal expansion of a composite containing spherical inclusions of different expansion coefficient is then obtained, again replacing the expansion coefficient of the matrix by that of the material as a whole. When the shear strain around the inclusion becomes large enough for plastic flow to occur, it suffices to modify the shear modulus approximately, since most of the shear strain energy is concentrated at the matrix-inclusion interface. The strain filed about an infinitely long cylindrical inclusion can also be resolved into a uniform dilation and a short-range shear strain field, and expressions for the thermal expansion of a composite with long fiber inclusions, randomly oriented, are obtained in a similar manner. Keywords Thermal expansion, Analytical solutions, Composites, Spherical and cylindrical inclusions.

Descriptors:

• *THERMAL EXPANSION
• *COMPOSITE MATERIALS
• BULK MODULUS
• IMPURITIES
• CAVITIES
• PLASTIC FLOW
• PARTICLES
• FIBERS
• MODULUS OF ELASTICITY
• PLASTIC PROPERTIES
• STRAIN RATE
• ORIENTATION(DIRECTION)
• COEFFICIENTS
• ENERGY
• EXPANSION
• FIBERS
• MATERIALS
• SHEAR STRENGTH
• SHORT RANGE(DISTANCE)
• SOLUTIONS(GENERAL)
• STRAIN(MECHANICS)

Subject Categories:

• Laminates and Composite Materials
• Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE