ELREEDYMAN

  Blasts are not always caused by combustion; they can also result from any rapid release of energy that creates a blast wave. The real examples as a bursting pressure vessel from which compressed air expands, or a rapid phase transition of a liquid to a gas as in oil and gas industry. It can be happened also from a bomb effect that measure it by trinitrotoluene (TNT).

Blast Load Calculation

The loads resulting from a blast are created by the rapid expansion of the energetic material, creating a pressure disturbance or blast wave radiating away from the explosion source. Blast pressure is more properly overpressure, because it is relative to ambient conditions.

Shock waves are high-pressure blast waves that travel through air  at a velocity faster than the speed of sound and these waves are characterized by an instantaneous increase in pressure followed by a rapid decay.

The pressure waves are lower amplitude and travel below the speed of sound. These waves are characterized by a more gradual increase in pressure than a shock wave, with a decay of pressure much slower than a shock wave.  In most cases, shock waves have a greater potential for damage and injury than pressure waves.

The calculation of the pressure due to blast load is calculated by loss prevention engineer, as it depends on the type of hydrocarbon and its components. There are some equation as guideline for the load calculation in the eBook.

The Problem in blast resistance building design that there are limit resources as it is available only ASCE, some military publications and up to date researches.

The reason of the structure damage is due to it is affect by pressure and suction within milli second you can see that in this video

Blast Design Approach

The design based on your requirement for structure performance after explosion. Are you need to have a minor cracks or major crack or you accept the structure failure?. Based on that, define the allowable defermation for every member when it reach to the platsic limits. The design considering the few second effect high load on the materials behaviour

The calculation is done through a spread sheet to check every element behaviour separately under platsic limit after cracks. Really there is no specifc software avilable to do that; however you can use any structure software to calculate the structure natural frequency. This eBook Blast Resistance Building Design presents an example for concrete control room design calculation by using excel sheets.

Strengthening Existing Building

In case of existing building; it needs another calculation for strengthening or using CFRP. Using CFRP is new tcehnque use in blast resistance but it is very easy in application rather than the conventional strengthening method even if you have a masonary bricks that presnts in ASCE. To do your design in proper way it will be discussed through 3 webinars about blast resitance design with comperhensive materials and Free excel sheet tools.