Nonlinear Dynamic Analysis of Reinforced Concrete and Steel Plane Frames under Blast Loading

Abstract

<p> This study deals with a method of analysis and the associated computer program that can capture the full nonlinear response of twodimensional reinforced concrete and steel plane frames subjected to dynamic loads, including blast and impact. Most of the relevant parameters that are normally neglected by similar available analysis tools have been considered in the present study. These include tension stiffening and concrete cracking, confinement effect and strain rate effect. Interaction between axial and bending deformations has also been accounted for. Four different constitutive models for concrete have been used and compared to each other together with multiple formulae accounting for the strain rate effect. The proposed analysis procedure was verified against other sophisticated software and experimental results and has proven to be a reliable means of analysis. </p> <p> The strain rate effect is shown to be a key parameter that plays an important role in the overall behaviour of structures under blast loads. Neglecting this effect does not necessarily lead to a more conservative design because it increases the overall stiffness of the structure which causes it to attract higher forces. This increase is proportional to the strain rate, which makes it particularly important in the case of blast loading where the strain rate can reach up to 1000 sec⁻¹. </p>