Explosive Stress: Shock , Blast, and Venting

DOE-HDBK-3010-94

3.0 Liquids; Aqueous Solutions

3.2.2

E xp losive S tress: S h ock , B last, an d V en tin g

Liquids may be subdivided by the shock generated by detonation-like reactions or by shear

stress at the surface generated by the accelerated airflow from the blast. Venting of

pressurized liquid phenomena is related to explosions as well.

3.2.2.1

S h ock E ffects

Steindler and Seefeldt (1980) provide an empirical correlation to experimental data on the

fragmentation of metals and aqueous solution by detonations [energy releases in

microseconds with brisance (shattering effect)] (Ayer, et al., May 1988). The experiments

performed by others were used to relate releases to mass ratios (i.e., ratio mass of inert

material to TNT equivalent) of 1 to 15. The experiments were conducted with the condensed

phase explosive embedded or contiguous to the material affected. Estimates of the ARF and

size distribution for various mass ratios up to 1000 are provided in Appendix C of

Ayer, et al. (May 1988) for a GSD (Geometric Standard Deviation, the slope of the line on

log probability plot) of 8. The GSD is much greater than normally assumed (GSD 2) due to

potential uncertainties regarding actual energy distribution. The fragmentation of only a

portion of the inert material occurs when MRs are large, and the fraction of shock energy

absorbed by this unknown portion of material is likewise unknown.

All inert material is driven airborne as particulates in the respirable size range for an MR of

one. The volume of material exposed to the shock effects of the explosion is essentially

constant for an explosive charge of a given size as the surface area in proximity to the charge

is fixed. However, as the amount of inert material increases, the fraction of the total mass

exposed to significant shock effects in that volume decreases. Given the potential

uncertainties of the data, this simple relationship will be used to extrapolate respirable

releases from the point of maximum release (i.e., MR = 1).

A respirable release of inert mass equal to the TNT equivalent for the detonation (to a

maximum of 100% release) is considered to bound the Steindler and Seefeldt (1980)

correlation. This assumption is supported by numerical comparison. For MRs of 5, 10, and

15, the combined ARF x RF values predicted by the correlation for a GSD of 2 are 4E-3,

6E-4, and 3E-4 respectively. For MRs of 5, 10, and 15, the combined ARF x RF values

predicted by the correlation for a limiting GSD of 8 are 2E-1, 9E-2, and 7E-2 respectively.

The simple method used by this handbook would predict combined ARF x RF values of

2E-1, 1E-1, and 7E-2, which correlate with the values for a GSD of 8 that are believed to be

very conservative.

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