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Airblast Shock Wave Equation and Calculator

Airblast Shock Wave Force Equation and Calculator

An air blast is an airborne shock wave that results from the detonation of explosives. The severity of an air blast is dependant on explosive charge, distance, and especially the explosives confinement.

${\displaystyle P=K{\left[\frac{R}{Q^{0.33}}\right]}^{-<!--\; -\; -->1.2}}$

where
P = pressure, kPa
K = state of confinement
Q = maximum instantaneous charge, kg
R = distance from charge, m

Typical K factors

Unconfined = 185
Full confined = 3.3

Expected damage (kPa)

0.33 = Windows rattle
0.7 = 1% of windows break
7.0 = Most windows break, plaster cracks
30.0 = Risk of damage to ear drums

Source:

• Dyno Nobel Asia Pacific Pty Limited
  Blasting and Explosives Quick Reference Guide (Mining Industry)
• Blast operational Overpressure Model. An Air blast Prediction Method, Air Force Weapons Laboratory
  AD-A182 0025

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