Dynamic Analysis by Extra Fast Fourier Transform

by Jethro W. Meek, Grad. Student; Dept. of Civ. Engrg., Rice Univ., Houston, TX,
Anestis S. Velestos, Brown and Root Prof. of Engrg. and Chmn. Dept. of Civ. Engrg.; Rice Univ., Houston, TX,

Serial Information: Journal of the Engineering Mechanics Division, 1972, Vol. 98, Issue 2, Pg. 367-384

Document Type: Journal Paper


A method based on the Discrete Fourier Transform (DFT) is presented for evaluating the dynamic response of any discrete, time invariant, linear system to an excitation, the spatial distribution of which is constant and the timewise variation of which may be represented by a string of equally spaced impulses of arbitrary magnitudes. In addition to being faster and more efficient than available DFT approaches, the method may be adopted to the processing of arbitrarily long excitations as a series of short, independent segments. The length of the individual segments may be chosen to optimize computational efficiency. The method consists of taking advantage of the periodicity implicit in the DFT approach and evaluating first the response of the system to a periodic extension of the excitation. A simple corrective solution is then superposed which converts the periodic response to the desired transient response. The method is illustrated by two numerical examples.

Subject Headings: Dynamic analysis | Excitation (physics) | Numerical methods | Spatial distribution | Arbitration | Fourier analysis | Dynamic response | Linear functions

Services: Buy this book/Buy this article


Return to search