From quasi-static to rapid fracture

摘要: Four fracture profiles corresponding to four diOEere1~t crack velocities are studied on trie same sample and show existence of a crossover lengthscale ( decreasmg with the velocity. For lengthscales larger thon (, previously reported roughl~ess index ct 0.84 is recovered. At smaller than profile lits quasi-static (QS) hypothesis, 1-e-, measured roughness close (~s CI 0.45. It now clearly established that surfaces can be considered as self-affine objects. After pioneering work Mandelbrot et ai. (l), many experiments using various experi-