Dynamic Analysis of Structures by the DFT Method

Abstract

Following a brief review of the Discrete Fourier Transform (DFT) method of analyzing the dynamic response of linear structures, the limitations and principal sources of potential inaccuracies of this approach are identified, and an evaluation is made of the nature and magnitudes of the errors that may result. Two versions of a modification are then presented which dramatically improve the efficiency of the DFT procedure, and the relative merits of the two techniques are examined. The concepts involved are developed by reference to single‐degree‐of‐freedom systems, and they are illustrated with the aid of judiciously selected numerical solutions.