Damping and stiffness coefficients of elastomer rings and their optimised application in rotor dynamics: theoretical investigations and experimental validation

Abstract

Dynamic systems suffering from instability or resonance problems often lack sufficient damping to reduce vibrations to an acceptable level. The authors developed a simplified approach for the proper selection of elastomers and an optimised design of ring geometry. Both the non-linear static behaviour and the contact problem as well as the temperature and frequency dependent thermo-viscoelastic behaviour are represented by equations derived from the theory of elasticity and were proven by experiments. Based on the material’s Master-curve, design charts for simple rotor systems were developed as a graphical approach in order to reveal the complex relationship between the rotor and elastomer parameters. The numeric solution can be simplified with the help of Master-curves, since the relevant model-parameters in terms of internal degrees of freedom eliminate the frequency dependence from the damping and stiffness matrices.

Additional information

Notes on contributors

A Bormann

Dipl-Ing. Alexander Bormann, born 1968, has worked as a research assistant at the Institute of Aeronautics and Astronautics at the Technical University of Berlin since 1997. He is a professional aircraft electrical engineer. After his professional training he studied aeronautics in Kiev, Ukraine and Berlin, Germany, where he did his degree in 1997. His research activities are in the fields of structural and rotor dynamics, wind turbines, optimised system design as well as advanced materials and technologies in flexible aero-structures and lighter than air crafts.

In his comprehensive research, under the supervision of Prof. Gasch, he tackles the optimised design of elastomer bearings for vibration damping of rotating machinery. The presented publication gives a brief outlook of this work which has nearly reached completion.

R Gasch

Prof. Dr.-Ing. Robert Gasch, born 1936, has taught structural dynamics, vehicle and rotor dynamics at the Institute of Aeronautics and Astronautics of the Technical University of Berlin since 1972.

Before that time he worked in the German industry of Turbomachinery (Siemens KWU) and with the Schenck-Company, Darmstadt (Balancing Machines). Together with colleagues he published very successful books on “Strukturdynamik I/II” (1987/89), “Rotordynamik” (2nd ed. 2002) and Windpowerplants (4th ed. 2002).