ORIGINAL CONTRIBUTION Effect of Plate Curvature on Blast Response of Structural Steel Plates Veeredhi Lakshmi Shireen Banu 1 • N. V. Ramana Rao 2 • Veeredhi Vasudeva Rao 3 Received: 25 April 2015 / Accepted: 31 March 2018 Ó The Institution of Engineers (India) 2018 Abstract In the present work an attempt is made, through simulation studies, to determine the effect of plate curva- ture on the blast response of a door structure made of ASTM A515 grade 50 steel plates. A door structure with dimensions of 5.142 m 9 2.56 m 9 10 mm having six different radii of curvatures is analyzed which is subjected to blast load. The radii of curvature investigated are infinity (flat plate), 16.63, 10.81, 8.26, 6.61 and 5.56 m. In the present study, a stand-off distance of 11 m is considered for all the cases. Results showed that the door structure with smallest radius of curvature experienced least plastic deformation and yielding when compared to a door with larger radius of curvature with same projected area. From the present Investigation, it is observed that, as the radius of curvature of the plate increases, the deformation mode gradually shifts from indentation mode to flexural mode. The plates with infinity and 16.63 m radius of curvature have undergone flexural mode of deformation and plates with 6.61 and 5.56 m radius of curvature undergo inden- tation mode of deformation. Whereas, mixed mode of deformation that consists of both flexural and indentation mode of deformations are seen in the plates with radius of curvature 10.81 and 8.26 m. As the radius of curvature of the plate decreases the ability of the plate to mitigate the effect the blast loads increased. It is observed that the plate with smaller radius of curvature deflects most of the blast energy and results in least indentation mode of deforma- tion. The most significant observation made in the present investigation is that the strain energy absorbed by the steel plate gets reduced to 1/3 rd when the radius of curvature is approximately equal to the stand-off distance which could be the critical radius of curvature. Keywords Blast response Á Plate curvature Á Explosive impact load Á Curved plates Introduction Explosions within or in the near vicinity of a military structure can cause a serious damage to external and internal steel structural plates and frames. Generally, to strengthen the external steel plates, a variety of stiffeners are welded to the steel plates. Thus, a variety of blast resistant plate structures that can withstand explosion impact were designed for various operational and safety requirements. Such a blast resistant structure could be constructed as stiffened flat steel plate, curved steel plate or even a sandwich structure. There are a number of applications of these studies in the construction of military, civil, aerospace, marine infrastructure, on-shore and off-shore oil exploration missions. There have been a number of studies both experimental and theoretical on the blast response of steel plates with flat geometries. Previous studies also include stiffened flat steel plates with a variety of stiffeners. However, in the litera- ture, studies on the blast response of curved steel plates are very limited. Steel plates with a predefined curvature offer much higher resistance and better response to blast loads. Ming-Wei et al. [1] conducted an investigation on the blast resistance of a stiffened door structure, in which they used & Veeredhi Lakshmi Shireen Banu vlsbanu@yahoo.co.in 1 Department of Civil Engineering, MREC (Autonomous), Maisammaguda, Dhulapally, Secunderabad 500100, India 2 National Institute of Technology, Warangal 506004, India 3 Department of Mechanical and Industrial Engineering, CSET, University of South Africa, Florida 1710, South Africa 123 J. Inst. Eng. India Ser. A https://doi.org/10.1007/s40030-018-0292-9