Methods for impact analysis of shipping containers

This report reviews methods for performing impact stress analyses of shipping containers used to transport spent fuel. The three methods discussed are quasi-static, dynamic lumped parameter; and dynamic finite element. These methods are used by industry for performing impact analyses for Safety Analysis Reports. The approach for each method is described including assumptions and limitations and modeling considerations. The effects of uncertainties in the modeling and analyzing of casks are identified. Each of the methods uses linear elastic structural analysis principles. Methods for interfacing impact stresses with the design and load combinations criteria specified in Regulatory Guides 7.6 and 7.8 are outlined. The quasi-static method is based on D'Alembert's principle to substitute equivalent static forces for inertial forces created by the impact. The lumped parameter method is based on using a discrete number of stiffness elements and masses to represent the cask during impact. The dynamic finite element method uses finite element techniques combined with time integration to analyze the cask impact. Each of these methods can provide an acceptable means, within certain limitations, for analyzing cask impact on unyielding surfaces. 25 refs., 23 figs