MODAL ANALYSIS: TWENTY YEARS BACK - TWENTY YEARS AHEAD.

Modal analysis has involved and will continue to involve the combination of several evolving technologies. In the measurement stage, the technology of digital signal processing and discrete transforms is of primary importance in terms of making accurate measurements and understanding the relative significance of the errors that remain. The understanding of this technology often is the limiting factor concerning the successful estimation of modal parameters. In the estimation stage, the estimation methods are changing rapidly due to the transfer of existing technology from other fields where estimation methods have been more common over the past several decades. Finally, the impact of the technology concerned with solid-state electronics on both the data acquisition hardware and the computational hardware has made advanced measurement and estimation techniques, that were impractical five years ago, routinely accessible.