STRAIN AND STRESS AT THE FRACTURE OF PERCOLATIVE MEDIA.

We measured the strain and the stress of a perforated metal foil and of a diluted elastic network near the percolation threshold. We used two different techniques: in the first, the strain is increased continuously and monotonically until the system ruptures, whereas in the second, it is the stress which is increased monotonically. We determined the critical exponent of the fracture stress sigma //f approximately (p//c-p)**T**f, with T//f equals 2. 5 plus or minus 0. 4 and the critical exponent of the fracture strain epsilon //f approximately (p//c-p)** minus **T**u with T//u equals 1. 4 plus or minus 0. 2. A theoretical interpretation of the results is proposed within the framework of the nodes-links-blobs picture.