Modal Analysis Based on the Random Decrement Transform
J. C. Asmussen, Rune Brincker, Sabrin R. M. Ibrahim · VBN Forskningsportal (Aalborg Universitet) · 1998
During the last years several papers utilizing the Random Decrement transform as a basis for extraction of modal parameters from the response of linear systems subjected to unknown ambient loads have been presented. Although the Random Decrement technique was developed in a decade starting from the introduktion in 1968 the technique seems still to be attractive. This is probably due to the simplicity and the speed of the algorithm and the fact that the theory of the technique has been extended by introducing statistical measures such as correlation functions or spectral densities. The purpose of this paper is to present a state-of-the-art description of the Random Decrement technique where the statistical theory is outlined and examples are given. But also new results such as estimation of frequency response functions and quality assessment are introduced. Special attention is given to the theoretical background for the application of the Random Decrement transform to ambient measurements.