Abstract

Specific computer programs for identification in modal analysis of structures are not economical, and they may not always be available. This paper presents a technique for simple optimization, getting fast and quality results, in the estimation of the damping ratios for each separate mode, and that can be resolved with a demo version (downloadable for free from the internet) of commercial optimization software. It is suitable for low levels of structural damping (or non-frequency-dependent damping), which are those that appear in large structures. Likewise, it is not necessary for the modes to be separate, or even that the magnitude of the near modes be less than that of those with which we are working; within the algorithm movable residual complements optimize their position according to the frequency and vertical axes (the response magnitude), to take into account the influence of the modes outside the considered range. In addition, it is not very sensitive to the presence of noise in the signal.