Multilevel parallel optimization using massively parallel structural dynamics

A large scale optimization of an electronics package has been completed using a massively parallel structural dynamics code. The optimization goals were to maximize safety margins for stress and acceleration resulting from transient impulse loads, while remaining within strict mass limits. The optimization process utilized nongradient, gradient, and approximate optimization methods in succession to modify shell thickness and foam density values within the electronics package. This combination of optimization methods was successful in improving the performance from an infeasible design which violated stress allowables by a factor of two to a completely feasible design with positive design margins, while remaining within the mass limits. In addition, a tradeoff curve of mass versus safety margin was developed to facilitate the design decision process. These studies employed the ASCI Red supercomputer and utilized multiple levels of parallelism on up to 2560 processors. In one portion of this optimization study, a series of calculations were performed on ASCI Red in four days, where an equivalent calculation on a single desktop computer would have taken greater than 10 years to complete.