Definition - What does Overpressure mean?
Overpressure is a type of pressure brought about by shockwaves more powerful than average atmospheric pressure. These shockwaves may be caused by several things, like an explosion or sonic boom.
Overpressure can be used in the measurement of the effects of thermobaric bombs and nuclear weapons.
Overpressure is also known as blast overpressure.
Corrosionpedia explains Overpressure
In order to measure blast effects, accurate determination of the overpressure amount should be made. Overpressure, or the pressure beyond normal atmospheric amounts, is measured in pounds per square inch (psi).
Overpressure is associated with damaging outcomes in terms of firing weapons and explosive detonations. Exposure to blast overpressure leads to injury, particularly to hollow systems in the body such as gastrointestinal, auditory and respiratory.
To put it into perspective, a 2 psi overpressure can cause collapse of residential structures, destruction of brick walls as well as injuries. If this amount of overpressure is doubled, most buildings are likely to collapse along with cases of injuries and fatalities. With 10 psi overpressure, even reinforced or concrete buildings can be severely damaged. Limbs can be detached as well, along with severe heart and lung damage. At 20 psi, heavily reinforced concrete buildings can be seriously damaged or even demolished.
Therefore, overpressure calculation is vital to prevent the disastrous effects of explosions.