Modeling for Non-Shock Initiation
A model is being developed to include non-shock energy contributions to explosive detonation. This model does not attempt to include all possible specific initiation mechanisms at the mesoscale, but instead looks at cumulative energy in the explosive through experimental calibration of a small number of coefficients. Both shock pressure and shear stress are accounted for in the summation. The model is designed to be robust, fast-running, and relatively simple to calibrate. The model is implemented into the CTH wave code as an extension to the existing History Variable Reactive Burn (HVRB) model currently used for shock initiation. The expression in the extended model uses the functional form of the Johnson-Cook strength model, as that relation contains terms for confinement, strain and strain rate, which contribute to the overall energy deposition. This form is not unique, other expressions will be examined that may be more comprehensive, but the current relation has provided reasonable results.
KeywordsSandia National Laboratory Shock Pressure Explosive Material Shock Initiation Explosive Detonation
Unable to display preview. Download preview PDF.
- 1.Todd, S.N., Dissertation: Non-Shock Model for Plastic Bonded Explosive PBXN–5: Empirical and Theoretical Results, New Mexico Institute of Mining and Technology, April 2007.Google Scholar
- 2.Hertel, Eugene S. and Kerley, Gerald I., CTH Reference Manual: The Equation of State Package, SAND98-0947, pp 57-59, April 1998.Google Scholar
- 3.Rae, Philip J., Compression Studies of PBXN-5 and Comp B as a function of Strain-Rate and Temperature, Report, Los Alamos National Laboratories, July 2008.Google Scholar
- 4.Johnson, G. R. and Holmquist, T. J., Test Data and Computational Strength and Fracture Model Constants for 23 Materials Subjected to Large Strains, High Strain Rates, and High Temperatures, LA-11463-MS, Los Alamos National Laboratories, January 1989.Google Scholar