Effect of Interfacial Roughness Parameters on the Fiber Pushout Behavior of a Model Composite

The effect of interfacial roughness on the frictional sliding in composites has been studied using fiber pushout and pushback tests on a model composite of Plexiglas rods in an epoxy matrix. Different extents of roughness were introduced on the Plexiglas rods and the resulting roughness profiles measured. The roughness profiles were characterized using six different roughness parameters. An attempt was made to find a correlation between the sliding resistance and the selected roughness parameters. A parameter defined as the maximum coefficient in the Fourier transform of the roughness profile was found to yield the best correlation. If the roughness introduced is periodic, then the pushout traces exhibit periodic dips, but the magnitude of this periodic dip is significantly smaller than the seating drop obtained from pushback tests.