Static and Dynamic Buckling of Shallow Arches

The static and dynamic buckling behaviors of a shallow, simply supported sinusoidal arch subjected to both a uniformly distributed step pressure load and a purely impulsive load are considered. Five equilibrium paths are obtained for the arch under static loading conditions. Critical static loads corresponding to two different instability modes and based on characteristics in the load displacement curve are obtained numerically. Critical dynamic loads, corresponding to three different instability modes, are obtained from a numerical procedure in which buckling criteria are based on characteristics in the time response of the structure. The influence of damping on the various dynamic stability regions and the dynamic response of a preloaded arch are observed and discussed

Advanced Computer Architecture for Engineering Analysis and Design.

The design and development of an advanced computer architecture that supports the parallel implementation of the finite element method of engineering analysis is presented. The computer consists of an array of asynchronous processors with both nearest-neighbor (12 neighbors) and global bus communication capabilities. A controller is attached to the global bus and supports the development of the finite element model and desired solution technique for downloading to the array. A new asynchronous solution technique is implemented and its performance compared to a parallel Jacobi algorithm, also implemented on the computer. Speedup and efficiency factors are given for both the Jacobi and asynchronous algorithms. Three tools were developed to support performance analysis: A four-processor prototype of the architecture, a software emulator, and software execution graphs. Each is discussed in detail. The results clearly indicate that the modified Amdahl's Law does not accurately predict the maximum speedup achievable with parallel processor systems. In general, the lower bound on speedup for this architecture is of O(.57N) where N is the number of processors being used for a particular analysis. An extension to nonlinear finite element analysis is also discussed.Ph.D.Computer scienceUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/159596/1/8324233.pd