STATISTICS OF FRACTURE SURFACES

Abstract

Experimental measurements of the roughness exponent ζ of some fracture surfaces are reported. Whatever the fracture mode, for unbranched (aluminium alloy) or branched (Ni3Al) surfaces, ζ is found quite close to 0.8, in accordance with other experimental determinations, but not with theoretical predictions of standard 3-d models. The complete height distribution for the complex branched structures is shown to slowly decrease with increasing altitude. It implies a power-law behavior for the low order moments which is experimentally recovered. Exponents reveal different from that of gaussian distributions.