On the cut-off value of negative triaxiality for fracture

Although yield condition of metals does not strongly depend on it, mean stress plays an important role in fracture of metals. A cut-off value of the stress triaxiality equal to −1/3, below which fracture never occurs, was derived analytically from the fracture locus in the principal strain space experimentally reported from upsetting tests. It was found that this result is consistent with tensile tests under hydrostatic pressure (Bridgman...