a comparison of experimental, operational, and combined experimental-operational parameter estimation techniques

A modal analysis aims at the identification of the modal parameters of a test structure from the measured vibratory behaviour. Traditionally, both the input forces and the resulting responses are measured. However, in many applications it is not possible to measure (all) the input forces. During the last decade, two new classes of modal parameter estimation techniques have been developed to overcome this problem: the operational techniques and the combined experimental-operational techniques. Operational modal analysis techniques can identify the modal parameters from the responses of the structure; they do not require the input forces. The combined experimental-operational techniques, only require a part of the input forces to estimate the modal parameters. The work presented in this paper is part of the evaluation process of these new modal parameters estimation techniques; it compares the modal parameters provided by the operational and combined experimentaloperational modal analysis techniques with the modal parameters obtained with the experimental modal analysis technique. © (2006) by the Katholieke Universiteit Leuven Department of Mechanical Engineering All rights reserved.