A study of the collapse of spherical shells, part I: Uncertainty quantification

Current and future Department of Energy (DOE) missions will increasingly rely on large-scale simulations for scientific guidance supporting issues of national importance. Arms control agreements have provided the impetus for national directives to cease production of new strategic weapons and end nuclear testing. Validated numerical methods must be employed in determining the reliability of specific weapon components, including the overall weapon system. The validated numerical models must, however, be based on accurate information of each component's geometry and material properties in an aged condition. To better understand both the predictive capabilities of engineering analysis codes, and enhance the analyst's confidence in those predictions, an integrated experiment and analysis project has been developed. The focus of this project is to generate precise probabilistic structural response simulations using numerical models of commercially available, stainless steel spherical marine floats, under collapse loads, and compare with experimental results. The spherical marine float geometry was chosen because of its simple shape, yet highly complex nonlinear deformation behavior, leading to complex states-of-stress. There is also a wide variability associated with geometry and mechanical properties of commercially available (i.e., off-the-shelf) marine floats. The wide variability is not uncommon, and principally due to numerous forming processes, different operators, etc., which bulk production operations employ for a single material lot.