Nonlinear explicit analyses of RC columns under blast loading using Finite Element Method

The columns are utmost important and most vulnerable part of the structures, the ideology of strong column and week beam is to prevent total collapse of the building while resisting the lateral loads and therefore columns should be built with high safety parameters. Thus column with greater stiffness than beam is provided. The present work deals with three dimensional nonlinear finite element (FE) analyses of a reinforced concrete column subjected to blast loading. The finite element package ABAQUS/Explicit was used to model a reinforced concrete column and the concrete damage plasticity approach was used to define the non-linearity of concrete. The stress-strain response of concrete and reinforcement has been simulated using concrete damaged plasticity model and elastic-perfectly plastic model, respectively. TNT explosive has been simulated using Air blast interaction under CONWEP definition. Parametric sensitivity studies have been performed by varying the spacing between stirrups as 125, 175, 225 and 275 mm and also diameter of main reinforcement bars are varied as 16, a20, 25, 28 and 32 mm to determine the displacement and stress variations. Efforts are also made to determine the effects of incident blast wave falling on the different face of the column. It is observed from the results that modeled column structure undergo significant deformation with variations. It is also observed that blast resistance increases as the spacing between stirrups decreases. Also, deformation of the column decreases as the diameter of the reinforcement bars increases.