ABSTRACT

Continuing programs of national significance are pushing numerical simulation to new levels. These include the Federal Aviation Administration (FAA) Turbine Rotor Material Design program aimed at reducing the risk of rotor fracture, the Nuclear Regulatory Commission (NRC) program to assess the long-term safety of the nation's first underground high-level radioactive waste repository, the Department of Energy (DOE) Stockpile Stewardship program to replace underground nuclear testing with computationally based full weapon system certification, and the reactivation of the NASA space shuttle return-toflight efforts. The common denominator of all these program areas is the need to compute-with high confidence-the reliability of complex, large-scale systems involving multiple physics, nonlinear behavior, and uncertain or variable input descriptions.