| Abstract: | It was found that the breakup-time of jets formed by shaped charges of cylindrical symmetry is given very accurately by the formula:  This formula is obtained from a general principal applied here for the first time which says that the breakup-time of homogeneous ductile metals under very high strain rates is equal to the smallest initial dimension of the elongating metal divided by VPL . When applied to simple configurations such as a pipe which expands due to internal explosion this principal leads to a correct prediction of the average formed fragment dimensions. This principal provides for the first time an explanation to the experimental fact that metals' ductility can increase by an order of magnitude when the strain rate increases from 10−2 to 105 pro second. |
