International Journal of Impact Engineering 31 (2005) 307–325 Vertical impact shock response of a cask model on a rigid unyielding surface R. Rajendran, K. Prem Sai, Saju Joy, K.C. Krishnamurthy, S. Basu* BARC Facilities, Kalpakkam 603 102, India Received 7 August 2002; accepted 7 October 2003 Abstract Vertical impact shock response of a cylindrical cask on a rigid unyielding surface is of importance for nuclear transportation. Impact drop experiments were carried out on a 380 kg cask model for heights vary- ing from 0.52 to 7.5 m and acceleration was measured. An approximate analytical model was developed to predict the impact shock and was validated with impact hammers of 2 and 1000 kg for various drop heights. r 2003 Elsevier Ltd. All rights reserved. Keywords: Impact; Drop test; Cask; Hammer; Acceleration; Strain; Model validation 1. Introduction The ability of a nuclear package to withstand transportation shock is assessed by subjecting a sample package or a scaled model to test or other assessment for the normal conditions of transport [1]. A free drop to a distance of 9 m on a flat, essentially unyielding horizontal surface, striking the surface in a position for which maximum damage is expected is the stipulated hypothetical accidental condition for which the package has to withstand. The acceleration, velocity and displacement for 9 m end drop of a rubber buffer model cask was presented by Shappert [2]. Numerical tests were performed by Yagawa et al. [3] to understand the dynamic behaviour of lead cask under normal impact onto a rigid floor due to accidental fall from a height of 9 m. But the results showed wide variations in the peak acceleration for various computer codes that were used. McConnell and Soreson [4] demonstrated the applicability of fracture mechanics based methodology for ensuring cask integrity. Tests were performed in the side drop orientation at a temperature of 29  C with a circumferential mid-axis flaw into the cask body for each drop test. The safety of a cask against impact accident is controlled by the stiffness of the cask body and ARTICLE IN PRESS *Corresponding author. Fax: +91-4114-280282. E-mail address: dayalan 52@yahoo.com (S. Basu). 0734-743X/$-see front matter r 2003 Elsevier Ltd. All rights reserved. doi:10.1016/j.ijimpeng.2003.10.036