Linear thermal expansion coefficients for an epoxy/glass matte-insulated solid cast

Conference · Tue Mar 01 04:00:00 EST 1988 · Int. J. Thermophys.; (United States)

OSTI ID:5845997

Dudek, J A; Kargol, J A

Glass matte/epoxy-reinforced composites provide high-quality electrical insulation, structural integrity, and environmental protection in solid cast transformers. The thermal expansion characteristics of those composites are very important; the thermal expansion must be compatible with the conductor of the transformer in order to minimize stresses and prevent decohesion between the composite and the copper. The glass matte orientation and loading greatly influence the thermal expansion characteristics of the composite. A section was removed from a glass matte/bisphenol A epoxy-insulated, copper conductor wound cylindrical transformer coil. The linear expansion coefficients of the glass matte/epoxy composite were determined by differential dilatometry for three mutually perpendicular orientations with respect to the cylindrical coil. The expected reduction in thermal expansion of the epoxy in the tangential and the axial directions due to the glass matte, which produced improved thermal expansion compatibility with the copper windings, was demonstrated. The measured linear thermal expansion coefficients were compared with theoretical values derived from a model for thermal expansion of a two-dimensional isotropic composite filled with fiber randomly oriented in a plane. An alternate composite system used for solid cast coil transformers, consisting of a cycloaliphatic resin filled with silica flour, was also investigated for comparison.

• Research Organization: Square D Company, Milwaukee, WI (USA)
• OSTI ID: 5845997
• Report Number(s): CONF-861258-
• Conference Information: Journal Name: Int. J. Thermophys.; (United States) Journal Volume: 9:2
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
COMPOSITE MATERIALS
COPPER
DENSITY
DILATOMETRY
ELECTRIC COILS
ELECTRICAL EQUIPMENT
ELECTRICAL INSULATION
ELEMENTS
EPOXIDES
EQUIPMENT
EXPANSION
FIBERGLASS
MATERIALS
MATERIALS TESTING
MECHANICAL PROPERTIES
METALS
NONDESTRUCTIVE TESTING
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
ORGANIC POLYMERS
ORIENTATION
PETROCHEMICALS
PETROLEUM PRODUCTS
PHYSICAL PROPERTIES
POISSON RATIO
POLYMERS
RESINS
SHEAR PROPERTIES
SILICON COMPOUNDS
STRESS ANALYSIS
STRESSES
TEMPERATURE MEASUREMENT
TESTING
THERMAL ANALYSIS
THERMAL EXPANSION
THERMAL STRESSES
THERMAL TESTING
TRANSFORMERS
TRANSITION ELEMENTS
YOUNG MODULUS