explosives engineering Explosives engineering is the field of science and engineering which is related to examining the behavior and usage of explosive materials. Topics Some of the topics that explosives engineers study, research, and work on include: * Developmen ...

, sensitivity refers to the degree to which an

explosive An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An exp ...

can be initiated by impact,

heat In thermodynamics, heat is defined as the form of energy crossing the boundary of a thermodynamic system by virtue of a temperature difference across the boundary. A thermodynamic system does not ''contain'' heat. Nevertheless, the term is ...

, or

friction Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding (motion), sliding against each other. There are several types of friction: *Dry friction is a force that opposes the relative la ...

. Current in-use standard methods of mechanical (impact and friction) senstivity determination differ by the sample preparation (constant mass or volume is usually used; pile or pressed pellet), sample arrangement (confined/unconfined sample etc), instrument type, go/not go criteria, and the statistical analysis of results. Sensitivity,

stability Stability may refer to: Mathematics * Stability theory, the study of the stability of solutions to differential equations and dynamical systems ** Asymptotic stability ** Linear stability ** Lyapunov stability ** Orbital stability ** Structural st ...

and

brisance In explosives engineering, brisance (; , ) is the shattering capability of a high explosive, determined mainly by its detonation pressure. Practical uses Brisance is of practical importance for determining the effectiveness of an explosion in ...

are three of the most significant properties of explosives that affect their use and application. All explosive compounds have a certain amount of energy required to initiate. If an explosive is too sensitive, it may go off accidentally. A safer explosive is less sensitive and will not explode if accidentally dropped or mishandled. However, such explosives are more difficult to initiate intentionally.

Explosive train

Less sensitive explosives can be initiated by smaller quantities of more sensitive explosives, called primers or

detonator A detonator, frequently a blasting cap, is a device used to trigger an explosive device. Detonators can be chemically, mechanically, or electrically initiated, the last two being the most common. The commercial use of explosives uses electr ...

s, such as

blasting cap A detonator, frequently a blasting cap, is a device used to trigger an explosive device. Detonators can be chemically, mechanically, or electrically initiated, the last two being the most common. The commercial use of explosives uses electr ...

s. The use of increasingly less sensitive explosive materials to create an escalating

chain reaction A chain reaction is a sequence of reactions where a reactive product or by-product causes additional reactions to take place. In a chain reaction, positive feedback leads to a self-amplifying chain of events. Chain reactions are one way that sy ...

is known as an explosive train, initiation sequence, or firing train.

Classifications

High explosives An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An ...

are conventionally subdivided into two explosives classes, differentiated by sensitivity: *

Primary explosive An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An ...

s are extremely sensitive to mechanical shock, friction, and heat, to which they will respond by burning rapidly or detonating. * Secondary explosives, also called base explosives, are relatively insensitive to shock, friction, and heat. The dataset for 150 CHNOFCl energetic compounds is available.

References

Explosives {{explosive-stub