MODES IN UNIDIRECTIONAL COMPOSITES UNDER TRANSVERSE
P. Tandon , R. Y. Kim , and R. E. Dutton
paper reports on our attempts to demonstrate potential failure
modes under combined thermal and transverse loading of unidirectional
composites and to validate the predictions of an analytical
model through careful design and testing of composite specimens.
Several fiber/matrix combinations are being considered with
appropriate variations of the fiber-matrix interfacial bond
strength and processing conditions. The interfacial bond
strength is reduced in one set of specimens by applying
a release agent to the surface of the fiber prior to its
incorporation in the matrix. Curing is done both at room
and at elevated temperature to account for thermal residual
stresses induced from the mismatch in the coefficients of
thermal expansion of the constituents. The experimental
technique including specimen preparation, test procedures
and detection of the sequence of failure events is described.
The correlation between the experimental and analytical
results is fairly reasonable.