Special Methods for Large Systems

Abstract

In this book we focus on computational approaches to structural dynamics because the calculations required to find the response of a system to dynamic loads involves tedious and repetitive steps that are ideally suited to the computer. To make the codes in the book as readable as possible we avoid clever strategies that might be used in commercial codes to speed up calculations. For the small problems we solve as examples in the book, speed of computation is seldom an issue. However, real-world systems can be very complex and the time it takes to execute structural dynamics computations grows with problem size, particularly for nonlinear problems. In this chapter, we examine two approaches to deal with large problems. Both methods involve projecting the problem onto a smaller subspace to improve the speed of calculation. One downside is that such methods are approximate and, therefore, require care in application.