A computational approach for probabilistic analysis of water impact simulations.

NASA's development of new concepts for the Crew Exploration Vehicle Orion presents many similar challenges to those worked in the 1960s during the Apollo programme. However, with improved modelling capabilities, new challenges arise. For example, the use of the commercial code LS-DYNA, although widely used and accepted in the technical community, often involves high-dimensional, time-consuming and computationally intensive simulations. Because of the computational cost, these tools are often used to evaluate specific conditions and are rarely used for statistical analysis. This paper discusses an approach to capture what is learned from a limited number of LS-DYNA simulations to develop models that allow users to conduct interpolation of solutions at a fraction of the computational time. In this approach, response surface models are used to predict the system time responses to a water landing as a function of capsule speed, direction, attitude, water speed and water direction. Furthermore, these models can also be used to ascertain the adequacy of the design in terms of probability measures. This paper presents a description of the LS-DYNA model, a brief summary of the response surface techniques, the analysis of variance approach used in the sensitivity studies, equations used to estimate impact parameters, results showing conditions that might cause injuries and concluding remarks. [ABSTRACT FROM AUTHOR]