ANALYSIS OF BUILDINGS FOR BLAST LOADS

Abstract

The blast response of the structures has been drawing attention of engineers and scientists all over the world for both military and civilian fields. The military engineers so far have focused mainly on the analysis and design of blast resistant shelters for defense establishments. Very little published literature in the area of the blast effect on the framed multistoried buildings is available. The aim of the thesis is to study the response of the multistoried buildings to ground blast explosive. Explosives when detonated on or above ground, results in a very rapid release of large amounts of energy within a short time, thus generating a pressure wave in the surrounding medium known as a shock wave. This wave exerts loads of high intensity and short duration on structures in the vicinity of the blast. Explosives even from small charges when placed close to a structure would result in very high peak pressures and could lead to damage. In this dissertation work, a three dimensional non-linear transient dynamic finite element analysis of reinforced concrete buildings subjected to blast loads is proposed to be carried out. The analysis has been carried out using available software LS-DYNA as well as from a inhouse programme available. Further, the pre-processor used for modeling of the building is HYPERMESH. The blast wave is defined by two parameters, the potency of the explosive and its distance from the building. The change of blast wave properties with time and distance is considered on different elements of the structure, so that different blast loads are acting on different elements. Moreover, the 3D nature of blast loading and its different way of interactions on front, top, sides and rear faces of the structure has been modeled.