ABSTRACT
A number of experimental techniques have been developed to characterize the interface/interlaminar properties in fiber reinforced composites. These techniques in general can be classified into two different means depending on the nature of specimens employed and the scale of testing ( 4): one involves testing of single fiber microcomposites in which individual fibers are embedded in specially constructed matrix blocks of various shapes and sizes; and the other uses bulk laminates and short fiber composites to measure the interlaminar properties. Details of the latter test methods are discussed in Section 3. The test methods using the microcomposites include the single fiber compression test, the fiber fragmentation test, the fiber pullout test, the fiber push-out (or indentation) test and the slice compression test with a variety of specimen geometries and scales involved. In these tests, the interface bond quality is measured in terms of the interface fracture toughness, Gic, or interface shear bond strength, 'tb, for the bonded interface; and the interface frictional strength, 'tfr' which is a function of the coefficient of friction, IJ., and residual fiber clamping stress, qO' for the debonded interface. The important characteristic features of these test methods regarding the specimen preparation and interpretation of experimental data are discussed below.
