An increase of the spall strength in aluminum , copper , and Metglas at strain rates larger than 107 s 2 1

Abstract

Measurements of the dynamic spall strength in aluminum, copper, and Metglas shocked by a high-power laser to hundreds of kilobars pressure are reported. The strain rates in these experiments are of the order of 10 s, which cannot be reached in impact experiments. The free-surface velocity behavior associated with spallation is characterized by oscillations caused by the reverberations of the spall layer. An optically recording velocity interferometer system was developed to measure the free-surface velocity time history. This diagnostic method has the advantages of being a noninterfering system and produces a highly accurate continuous measurement in time. The spall strength was calculated from the free-surface velocity as a function of the strain rate. The results show a rapid increase in the spall strength, suggesting that a critical phenomenon occurs at strain rates ;10 s, expressed by the sudden approach to the theoretical value of the spall strength. © 1998 American Institute of Physics. @S0021-8979~98!08308-X#

16 Figures and Tables

Cite this paper

@inproceedings{Moshe1998AnIO, title={An increase of the spall strength in aluminum , copper , and Metglas at strain rates larger than 107 s 2 1}, author={Ella Moshe and Shalom Eliezer and Erez Dekel and A . Ludmirsky and Zohar Henis and M . Werdiger and I . B . Goldberg and Noam Eliaz and Dina Eliezer}, year={1998} }