Detonation
Definition
A supersonic shock wave coupled to a chemical reaction front, propagating through a high explosive at velocities between approximately 4,500 and 9,100 m/s. Produces brisance (shattering effect) alongside blast overpressure.
- Detonation speed range
- 4,500 to 9,100 meters per second
- Characteristic property
- Supersonic shock wave coupled to chemical reaction
- Primary effects
- Brisance (shattering) and blast overpressure
Common questions
What's the difference between detonation and deflagration?+
Detonation is a supersonic reaction propagated by a shock wave that travels at 4,500 to 9,100 m/s. Deflagration is slower (subsonic). High explosives like RDX, TNT, and PETN detonate. The shock wave in a detonation couples to the chemical reaction, producing both brisance (shattering effect) and blast overpressure.
What happens physically during detonation?+
The shock wave compresses each layer of explosive material, igniting it. The reaction front then drives the next layer, creating a chain reaction that travels through the material at supersonic speed. This produces a sharp impulsive overpressure spike followed by a negative pressure phase.
How fast does a detonation travel?+
Detonation velocities range from about 4,500 m/s in materials like ANFO to 9,100 m/s in materials like HMX. The exact speed depends on the explosive composition and conditions.
Related terms
- Deflagration
- A subsonic combustion front propagating through an explosive by thermal conduction. Characteristic of low explosives such as black powder and smokeless powder;...
- Brisance
- The shattering power of a detonating explosive, distinct from heave (bulk displacement). Measured by the Trauzl lead block test. High-brisance explosives (RDX,...
- Oxygen Balance
- A percentage expressing the surplus or deficit of oxygen in an explosive molecule relative to stoichiometric complete oxidation of carbon to CO2...
- Primary Explosive
- A high explosive sensitive enough to detonate from friction, spark, percussion, or flame without confinement or a separate booster. Examples: mercury fulminate,...
- Secondary Explosive
- A high explosive insensitive to normal friction, spark, and percussion; requires a primary explosive shock or blasting cap to initiate detonation. Examples:...
- ANFO
- Ammonium nitrate fuel oil: 94% ammonium nitrate prills + 6% diesel fuel oil. Detonation velocity approximately 4,500-4,800 m/s. The most widely used...
- API 579
- The American Petroleum Institute's Fitness-For-Service standard, which provides assessment methods for determining whether a damaged or corroded pressure vessel or piping component...
- BLEVE
- Boiling liquid expanding vapour explosion. Catastrophic failure of a vessel containing a superheated liquid, producing an expanding pressure wave and, if the...
- Chapman-Jouguet Velocity
- The minimum stable detonation velocity for a given explosive at a specific density, a thermodynamic property of the explosive composition. Used to...
- Corrosion Under Insulation (CUI)
- External corrosion of a pipe or vessel surface that occurs beneath thermal insulation, hidden from visual inspection, driven by moisture infiltrating the...
- Deflagration-to-Detonation Transition (DDT)
- The acceleration of a deflagrating burn front to supersonic detonation velocity, triggered by confinement. Relevant to understanding how improvised devices using low...
- Detonator
- A small initiating charge of primary explosive (lead azide, lead styphnate, mercury fulminate or DDNP) that converts an electrical, mechanical or pyrotechnic...
Explained in these topics
- Explosion and Pressure-Vessel FailureCombustion in which a coupled shock wave and reaction zone propagate at supersonic velocity. Produces a sharp impulsive overpressure spike followed by a sub-am...
- Explosives Classification: Low vs High, Primary vs SecondarySupersonic propagation of a reaction front driven by a shock wave through the explosive material. Velocities range from 4,500 m/s (ANFO) to 9,100 m/s (HMX). Ch...
- Explosives Classification: Low, High, Primary, Secondary, TertiaryA supersonic shock wave coupled to a chemical reaction front, propagating through a high explosive at velocities between approximately 4,500 and 9,100 m/s. Pro...
- Explosives: Definition, Types and ClassificationSupersonic decomposition driven by a shock wave that compresses and ignites the next layer. Reaction front travels at km/s. RDX, TNT, PETN detonate.