Software & Development Tools
Using the newly developed calculation methodology, it is possible to determine the vibration response of turbine blades with connecting elements, such as cover bands. This methodology is based on the Multiharmonic Balance Method, which approximates the static vibrations of a non-linear coupled dynamic system through periodic vibration. Using a test stand developed during the project, the calculation of necessary model parameters was determined. In order to guarantee broad practical application, this methodology is applied in a program code that can be combined with a variety of simulation programs used in industry. In this way, the project makes an important contribution to the optimal design of heavily loaded turbine blades.
» In the FVV we have a unique chance to work on complex topics such as the vibration behaviour of friction-dampened systems in a scientifically sound manner while remaining at all times practice-oriented. «
In the multiharmonic balance (HBM) project everything revolved around calculating vibration response.
The FVV project further enhances the vibration analysis and optimal design of dry-friction damped turbine blades.
Test stand to measure friction hysteresis for identifying contact parameters.
Turbine blades are subject to high static and dynamic loads. These cause blade vibrations, which can lead to severe damage. The use of connecting elements, such as cover bands for example, leads to a reduction of the vibration amplitude because of hardening and friction dampening. In order to design the connecting elements optimally, it is essential to have precise knowledge of the vibration behaviour of friction-dampened systems.
In order to model the friction dampening as realistically as possible, the Multiharmonic Balance Method was used for calculating the vibration. Thus the periodic, static vibrations of a non-linear connected dynamic system are approximated through the superimposing of harmonic vibrations. The modelling of the frictional contact occurs over one or more point-to-point contacts or through the adoption of two rigid planes in contact. A test stand developed in the project also makes it possible to experimentally determine friction hysteresis. This work forms the basis for determining the model parameters of friction coefficient and tangential stiffness.
With this new method the dynamic behaviour of friction-dampening structures can be calculated with real, expanded joints and thus the vibration response of turbine blades with friction contacts. At the same time it also considers the higher frequency rates of vibrations and vibration responses. In this way, the method is capable of depicting real applications and application areas. With the help of program codes, which can be combined with industrial simulations programs, the method can be directly implemented in practice.
High-order Harmonic Balance I | Optimisation of component joints considering multi-frequency vibration excitation and non-linear contact forces in frequency range | Project No. 961
High-order Harmonic Balance II | Optimisation of component joints considering multi-frequency vibration excitation and non-linear contact forces in frequency range | Project No. 1045 | DFG Funding ID 578360
Ninlinear Blade Vibrations | Improvement of the FoReBlade-code for nonlinearly coupled structures vibratory response under consideration of higher harmonic approaches | Project No. 1158
Public & FVV Funding
2008-04-01 to 2010-03-31 Part I
2010-07-01 to 2012-06-30 Part II
2014-01-01 to 2016-06-30 Part III
Dr.-Ing. Andreas Kayser | I+II
Dipl.-Ing. Markus Denk | III
Dr.-Ing. Pierre-Alain Masseray | III
General Electric (Switzerland) GmbH
Institute of Dynamics and Vibration Research (IDS) | Leibniz University Hannover
Head of Research:
Prof. Dr.-Ing. Jörg Wallaschek
Dipl.-Ing. Marius Bonhage | III
Dipl.-Ing. Anna Herzog | I-III
Dipl.-Ing. Ferhat Kaptan | III
Dipl.-Ing. Christian Siewert | I+II
Research Association for Combustion Engines eV
Lyoner Strasse 18
60528 Frankfurt am Main
T +49 69 6603 1345