Mechanical engineering,and engineering discipline born of the needs of the industrial revolution, is once again asked to do its substantial share in the call for industrial renewal. The general call is urgent as we face p- found issues of productivity and competitiveness that require engineering solutions, among others. The Mechanical Engineering Series is a series f- turing graduate texts and research monographs intended to address the need for information in contemporary areas of mechanical engineering. The series is conceived as a comprehensive one that covers a broad range of concentrations important to mechanical engineering graduate - ucation and research. We are fortunate to have a distinguished roster of series editors, each an expert in one of the areas of concentration. The names of the series editors are listed on page vi of this volume. The areas of concentration are applied mechanics, biomechanics, computational - chanics, dynamic systems and control, energetics, mechanics of materials, processing, thermal science, and tribology. Preface After15yearssincethepublicationofVibrationofStructuresandMachines and three subsequent editions a deep reorganization and updating of the material was felt necessary. This new book on the subject of Vibration dynamics and control is organized in a larger number of shorter chapters, hoping that this can be helpful to the reader. New materialhas been added and many points have been updated. A larger number of examples and of exercises have been included.