User orientated simulation strategy to analyse large drive trains in SIMPACK

Transcription

1 User orientated simulation strategy to analyse large drive trains in SIMPACK SIMPACK User Meeting / Dipl.-Ing. Thomas Hähnel / Dipl.-Ing. Mathias Höfgen 21. / 22. November 2007

2 Content Motivation, state of the art Modelling of a 3 MW wind turbine Parameter, shafts, bearing and gearing Gearbox and mainframe Simulation results Frequency domain Time domain Summary 2

3 Content Motivation, state of the art Modelling of a 3 MW wind turbine Parameter, shafts, bearing and gearing Gearbox and mainframe Simulation results Frequency domain Time domain Summary 3

4 Motivation for investigations Improvement and verification of simulation techniques to identify critical components and operating conditions already during the development process cost of faults in the product development process Analysis of damages by identification of critical natural frequencies and excitations as well as the recalculation of load cases by the usage of the MBS method costumer dynamic simulation of drive trains already during the development process! production prototyp idea first model development phase 4

5 Field of research Drive trains with up to several MW output power Operating with high dynamic loads Normally without stiff foundation 5

6 Field of research 6

7 Field of research 7

8 Content Motivation, state of the art Modelling of a 3 MW wind turbine Parameter, shafts, bearing and gearing Gearbox and mainframe Simulation results Frequency domain Time domain Summary 8

9 Modelling of a 3 MW wind turbine Assembly of a multibody-system simulation model for a wind turbine, 3 MW electrical power 90 m rotor diameter 3 point support 2 planetary gear stages 1 helical gear stage Available information: drawings, bearing stiffness, gearing data, load cases 9

10 Modelling of a 3 MW wind turbine Parameter Determination of parameter: mass of inertia, mass, centre of gravity Shafts Discretisation (FVA 95 part B), SimBeam, Import of FEMstructures Bearing Linear, nonlinear radial and axial bearing stiffness, complete bearing characteristic Gearing Programmed user routines with 6 DOF, linear, nonlinear stiffness, clearance Structure Consideration of flexible components (gearboxes, shafts) as modal reduced structures in the MBS model 10

11 Modelling of a 3 MW wind turbine Modelling of the bearings Modelling of the bearing by springdamper-elements and presetting of radial and axial bearing stiffness Consideration of the complete bearing characteristic Complete MBS model of a bearing Including the stiffness, the clearance and the friction in the bearing 11

12 Modelling of a 3 MW wind turbine Parameter Determination of parameter: mass of inertia, mass, centre of gravity Shafts Discretisation (FVA 95 part B), SimBeam, Import of FEMstructures Bearing Linear, nonlinear radial and axial bearing stiffness, complete bearing characteristic Gearing Programmed user routines with 6 DOF, linear, nonlinear stiffness, clearance Structure Consideration of flexible components (gearboxes, shafts) as modal reduced structures in the MBS model 12

13 Modelling of a 3 MW wind turbine Modelling of the gearing Usage of self-programmed functions Consideration of torsional, axial and radial DOF Clearance Linear (DIN 3990) or nonlinear tooth stiffness 13

14 Modelling of a 3 MW wind turbine Parameter Determination of parameter: mass of inertia, mass, centre of gravity Shafts Discretisation (FVA 95 part B), SimBeam, Import of FEMstructures Bearing Linear, nonlinear radial and axial bearing stiffness, complete bearing characteristic Gearing Programmed user routines with 6 DOF, linear, nonlinear stiffness, clearance Structure Consideration of flexible components (gearboxes, shafts) as modal reduced structures in the MBS model 14

15 Modelling of a 3 MW wind turbine Analysis of the gear box by a FEM model Mode shape: 232 Hz Mode shape: 328 Hz 15

16 Modelling of a 3 MW wind turbine Analysis of the mainframe by a FEM model Mode shape: 31 Hz Mode shape: 52 Hz 16

17 Modelling of a 3 MW wind turbine Consideration of flexible structures MBS model Definition of body properties Body connections by springs and dampers Excitation by forces and torques FEM model Import of the CAD model Creating the mesh Definition of material properties MBS with FEM structure Reduction of the FEM model by usage of techniques by Guyan and Craig Bampton 17

18 Modelling of a 3 MW wind turbine Simulation in the frequency domain Natural frequencies Animation of mode shapes Analysis of amplitudes und phase Transfer behaviour Transfer behaviour of the drive train under consideration of an excitation Estimation of different transfer path Campbell-Diagramm Comparison of natural frequencies and excitation Determination of critical operation points 18

19 Modelling of a 3 MW wind turbine Simulation in the time domain 19

20 Modelling of a 3 MW wind turbine Modelling of the wind forces Consideration of a wind field (wind shear, yawed flow) Calculation of the resulting forces for current position, each blade segment and each blade (according to the blade momentum theory) 20

21 Content Motivation, state of the art Modelling of a 3 MW wind turbine Parameter, shafts, bearing and gearing Gearbox and mainframe Simulation results Frequency domain Time domain Summary 21

22 Simulation results frequency domain ~ 1.0 Hz bending mode shape of the blades (flapwise) Amplitude of the blade sections, y-direction z x y 22

23 Simulation results frequency domain ~ 1.5 Hz bending mode shape of the blades (edgewise) Amplitude of the blade sections, z-direction z x y 23

24 Simulation results frequency domain ~ 5.5 Hz first torsional mode shape of the drive train 24

25 Simulation results frequency domain ~ 22.7 Hz bending mode shape of the gearbox and the main frame 25

26 Simulation results frequency domain ~ 40.6 Hz bending mode shape of the main frame 26

27 Simulation results frequency domain ~ Hz axial mode shape of the drive train against the gear box 27

28 Content Motivation, state of the art Modelling of a 3 MW wind turbine Parameter, shafts, bearing and gearing Gearbox and mainframe Simulation results Frequency domain Time domain Summary 28

29 Simulation results time domain Run up of a wind turbine Pitching of the blades Connecting of the generator 29

30 Simulation results time domain Run up of a wind turbine Forces in the gear stages and in the support of the gearbox 30

31 Simulation results time domain Emergency stop of a wind turbine Disconnecting of the generator Pitching of the blades, breaking 31

32 Simulation results time domain Emergency stop of a wind turbine Forces in the gear stages and in the support of the gearbox 32

33 Simulation results time domain The simulation of measured load cases allows the determination of Displacements, speeds and accelerations of the drive train components Forces and torques in shafts and clutches Bearing and gearing forces which could not or only with a large effort be determined during measurement campaigns. 33

34 Content Motivation, state of the art Modelling of a 3 MW wind turbine Parameter, shafts, bearing and gearing Gearbox and mainframe Simulation results Frequency domain Time domain Summary 34

35 Summary The MBS simulation can be a helpful tool during the design phase of large drive trains in large machinery applications It is an absolutely must to have the knowledge of all relevant natural frequencies of the drive train All the drive trains of different operation fields have similar dynamic properties in operation mode The simulation is much more cheaper than big measurement campaigns or the repair of drive train components 35

36 Thank You for Your Attention Technical University of Dresden Department of Mechanical Engineering Institute of Machine Elements and Machine Design Chair of Machine Elements Münchner Platz 3 D Dresden 36