Effects of Blast Loading on Engineering Structures – An Overview
Post GraduaƟon Student, Professor, Department of Civil Engineering, Dayananda Sagar College of Engineering, Shavige Malleshwara Hills, Kumarswamy Layout, Bengaluru, India.
The present study aims at providing an overview on the blast loading and blast effects on engineering structures. The use of vehicle bombs to aƩack city centers has been a feature of campaigns by terrorist organizaƟons around the world. A bomb explosion within or immediately nearby a building can cause catastrophic damage on the building’s external and internal structural frames, collapsing of walls, blowing out of large expanses of windows, and shuƫng down of criƟcal life-safety systems. Loss of life and injuries to occupants can result from many causes, including direct blast-effects, structural collapse, debris impact, fire, and smoke. The indirect effects can combine to inhibit or prevent Ɵmely evacuaƟon, thereby contribuƟng to addiƟonal casualƟes. In addiƟon, major catastrophes resulƟng from gas-chemical explosions result in large dynamic loads, greater than the original design loads of many structures. Due to the threat from such extreme loading condiƟons, efforts have been made during the past three decades to develop methods of structural analysis and design to resist blast loads. The analysis and design of structures subjected to blast loads require a detailed understanding of blast phenomena and the dynamic response of various structural elements. This paper presents a comprehensive overview of the effects of explosion on structures. An explanaƟon of the nature of explosions and the mechanism of blast waves has been highlighted.
technology, blast magnitudes have increased . Explosion within the structure or nearby structures can cause sudden or catastrophic damage to the building’s external and internal structural frames, collapsing of walls, blowing out large windows, loss of life and injuries to occupants, etc. Therefore, the structures are to be designed for an adequate level of blast resistance. However, designing of structures to be fully blast resistance is not realistic and economical . But with the help of current engineering and architectural knowledge one can enhance the new and existing structures to mitigate the effects of an explosion resulting due to blast.
It can be defined as the sudden conversion of potential energy into kinetic energy with the production and release of gas under pressure. The sudden liberation of energy causes increase in temperature and pressure so that the materials present are converted into hot compressed gases. Since these gases are at high temperature and pressure, they expand rapidly creating a pressure wave which is known as shock waves. It is a thin transitive area propagating with supersonic speed in which there is a sharp increase of density, pressure, and speed of the substance. They arise when the speed of the source wave is greater than the sound wave. A shock wave in air is generally referred to as blast wave .