A study of the micromechanics of the fiber-matrix interphase in monofilament composites, in monotonic loading, and cyclic fatigue

Thesis/Dissertation · Mon Jan 01 04:00:00 EST 1990

OSTI ID:5517713

Schadler, L S

Macroscopic properties of continuous filament composites are dependent on the fiber-matrix interphase behavior: the ability of the interphase to transfer load from the matrix to the fiber, and the energy absorbed during interphase failure. A mono-filament composite system was employed to study the fiber-matrix interphase because fiber/fiber interaction and processing variability are eliminated. Several methods were used to observe the interphase behavior of carbon/thermoplastic matrix mono-filament composites including a fragmentation technique to measure the interphasial shear stress and a Raman spectroscopic technique. The first goal was to alter the interphase in a controlled manner by treating the fiber surface, and then correlating fiber surface morphology, fiber surface energy, fiber strength, and matrix properties with interphase micromechanics. The second goal was to study the role of the interphase in cyclic fatigue. The effects of cyclic loading direction, frequency, and amplitude were studied. Damage was characterized by fiber matrix debonding, a reduction of the average interphase shear stress, and changes in the locus of failure as determined by scanning electron microscopy fractography.

• Research Organization: Pennsylvania Univ., Philadelphia, PA (United States)
• OSTI ID: 5517713
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
COMPOSITE MATERIALS
DAMAGE
ENERGY
FAILURE MODE ANALYSIS
FATIGUE
FIBERS
FREE ENERGY
INTERFACES
MATERIALS
MATRIX MATERIALS
MECHANICAL PROPERTIES
PHYSICAL PROPERTIES
STRESS ANALYSIS
SURFACE ENERGY
SURFACE PROPERTIES
SYSTEM FAILURE ANALYSIS
SYSTEMS ANALYSIS
THERMODYNAMIC PROPERTIES