Development of Improved Modeling and Analysis Techniques for Dynamics of ShellStructures

摘要

This report contains two related research thrusts: improved shell structuralmodeling for underwater acoustics and massively parallel computations of shell dynamics response. Improvements on the existing ANS shell elements have been made and implemented on a testbed software; the module was then delivered to NRL for their applications. In addition, the so-called frequency-window tailoring of finite element models has been developed so that very high-frequency components can be accurately modeled with relatively coarse finite element grids, thus resulting in about a factor of five to ten times larger element size than has been possible in conventional finite element modeling. Second, several parallel modules using the C language have been developed to run large-scale shell dynamics problems on the Connection Machines. These include: decomposer which takes as input an arbitrary mesh description, and produces a set of finite element data structures that can be loaded within one generic CM2 chip; mapper that assigns each of the data structures produced by the decomposer to a well defined chip; residual evaluator that controls the direct calculation of element residuals; element library that includes various finite elements; and visualization kernel that greatly facilitates the understanding of the computed results.