Modeling Shear Wall Structures

with Large Numbers of DOFs


by

Jack Demitz

Civil Engineer
Bechtel Corporation
Frederick, MD

 

Abstract


The evolution of the PC industry has had a profound effect on the field of finite element analysis. Structural models that were once run on mainframes and minicomputers using input decks that were processed in matter of hours or days, now can be run on a PC in a matter of seconds or minutes. Coupled with this increase in computing power, the price for this computing power has dropped significantly such that almost everyone has access to these resources.

As the cost of executing finite element analysis has dropped, the efficiency of most models developed by today's users have dropped. In the past, when the price of computing power was at a premium, the user had to pay attention to the ordering of nodes in the model such that the problem would be solved at a minimum of expense. Today, the price of computing is so cheap and the power of PCs are so great that it typically would cost the user more to optimize the node numbering. Furthermore, the increase computing power and advancements in software have allowed users to greatly increase the complexity of finite element models. As the complexity of the model increases, the burden on system resources increases, translating to increased solution time. For models with relatively few numbers of degrees of freedom, solution time is insignificant. When modeling structures with large numbers of degrees of freedom, solution time becomes a significant factor. Additionally, the increased complexity of models also greatly impacts the time to post process results.



The purpose of this presentation is to discuss the implications of modeling shear wall structures with significantly large numbers of DOFs. The impact of model complexity and the effect of node numbering on system resources are discussed. Methods for post processing are presented.



Biographical Information


For the past 3 and a half years, Mr. Demitz has been working for the Bechtel Power Corporation. His experience includes the design of turbine generator foundations, blast enclosures, and nuclear containment analysis.

Education


Bachelor of Science in Civil Engineering 1993, University of Delaware

Master of Science in Civil and Environmental Engineering 1999, University of Delaware

To view the entire presentation on-line select the following PowerPoint Presentation .ppt file:

Demitz.ppt