FRACTURE MODES IN FIBER NETWORKS

Two-dimensional fiber networks of varying disorder are studied with a quasi-one-dimensional model. When disorder increases, the process of f racture in the localized stage evolves continuously from crack propaga tion to uncorrelated microcracking. In larger systems the transition t akes place over a narrower range of disorder. Along with the change in the nature of fracture, the maximum of the tension on the network mov es from the beginning to the end of the fracture process. Irrespective of the size of the system, this always occurs around the same degree of disorder and becomes more distinct with increasing system size. At the thermodynamic limit, a discontinuous change is suggested in the ra tio of the strain at the first fiber failure to the strain at the fina l collapse.