Fragmentation Models Based on Void Coalescence
Abstract
In ongoing work that evaluates debris and shrapnel hazards in the National Ignition Facility target chamber, we use fragmentation models developed by Grady and colleaagues [D. E. Grady, J. Mech. Phys. Solids, Vol. 36, No. 3, 353-384, 1988]. Grady's models have wide application in the fragmentation community, and generally correlate well with experimental data (although anamolous results have recently been reported by Grady for a ceramic [D. E. Grady, Proceedings of 1998 Hypervelocity Impact Symposium, Huntsville, Alabama, 17-19 November 1998]). Because of our heavy reliance on these models (which are end state models based on energy conservation), we have reevaluated them by comparing their derivation with the predictions of detailed mesomechanical models of the nucleation and growth (NAG) of microcracks or voids to coalescence to cause fragmentation [D. R. Curran et al, Physics Reports, 147, Nos 5 & 6, 1987]. Our results show that the NAG-based models give similar results as Grady's models at very high strain rates (1 million/s), but can give significantly different results at lower strain rates.
- Publication:
-
APS Shock Compression of Condensed Matter Meeting Abstracts
- Pub Date:
- June 1999
- Bibcode:
- 1999APS..SHK..L302C