FRACTAL CHARACTERIZATION OF FRACTURE SURFACES BY SLIT ISLAND TECHNIQUE

Them is an increasing emphasis to link the concepts of quantitative fr actography and fracture mechanics in order to achieve a better underst anding of crack propagation in solids. This awareness has brought in s everal fracture surface characterizing parameters, one of which is fra ctal dimension determined either by slit island or profilometric techn ique. The existing analytical treatments to estimate fractal dimension by slit island technique (D(s)) possess some inherent subtle variatio ns. The effect of these variations on D(s) have been examined using th e results of a series of tests at subambient temperatures. The magnitu des of D(s) have been computed using four existing approaches, and att empts have been directed to search correlations between impact energy and D(s) evaluated by each of these approaches. It is established that definite correlations exist between these parameters irrespective of the method of estimating D(s); but the nature of these correlations de pends on the analytical treatment employed for evaluating D(s). These analyses are supplemented with an examination of D(s) vis-a-vis conven tional fractographs.