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 fracture in the localized stage evolves continuously from crack propagation to uncorrelated microcracking. In larger systems the transition takes place over a narrower range of disorder. Along with the change in the nature of fracture, the maximum of the tension on the network moves 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 ratio of the strain at the first fiber failure to the strain at the final collapse