SIMPACK User Meeting 2014 MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches Gerald Ochse University Kassel, IAF/MT Richard Schönen IST GmbH Aachen Carsten Träbing, Volker Ploetz Schaeffler Technologies GmbH & Co. KG
Content • Problem Statement, Goal, Implementation • Basis • Contact Situation • Force and Friction Models • Freewheel Clutch • Simulation • Experiment • Comparison • Summary MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches
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Problem Statement Initial Situation: • Software tools for the dynamic simulation of multi body systems (MBS) are available and well established • Models for internal contact and transfer of loads may be: • Either insufficient in terms of modeling contact mechanics and/or • Time-consuming in their application
Need for: • Proper modeling of contact physics • Consideration of global and local stiffness effects • Analysis of components in complete systems in full interaction
MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches
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Goals & Realization Goals: • To establish time efficient methods and algorithms for contacts in MBS systems • To make available different physical models for frictional forces • To fully implement in MBS simulation • To support ease of use with a Graphical User Interface
Implementation: • • • •
Adequate contact algorithms were cast in external Fortran routines Integration in commercial MBS-Program by standardized interfaces Simple contact model for validation vs. existing internal routines Extension of contact and friction models to consider effects of • Slip and sum velocities • Lubricant parameters • Surface roughness MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches
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Contact Situation Approach and Overlap of two Rigid Bodies • are defined by • Position • Velocity • Geometry
MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches
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Force Models of the UFEL Force Models: • Spring-Damper • DIN ISO 281 • Hertz elliptical • Wijnant (extension Hertz by lubrication) Spring-Damper: • Standard Contact • Simpack Force 18 g(L)
d WIJ
2 1 R x ɶ 3 4 ⋅ f (L) ⋅ ⋅M ⋅ ( F ⋅ R ⋅ ε ) ⋅ ( E '⋅ π ) 3 Ry = 1 ( 6 ⋅ κ ) 3 ⋅ K ⋅ Vhyd
e
δ FFD = s ⋅ c x − d ⋅ v s 1 0.8 0.9 ⋅B
δ ⋅10 F281 = 3.97 5
δ ⋅ 2R ⋅ ε K FHZ = 2 3R 2 κε 3 E' ⋅ π
3 2
q(L) R ⋅ δ δWIJ = 1 − p(L) ⋅ x ⋅ M HZ R y
MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches
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Friction Models of the UFEL µ
stat Friction Models: • constant (static/dynamic) µdyn • Drozdov / Gavrikov • O‘Donoghue / Cameron vvgleit vtrans vtrans slide • Misharin 0.25 0.25 1 Raa R ⋅⋅ • Benedict & Kelly µ DRG = 0.63e − 6 0.8 ⋅ Vslide ⋅ ν + V ⋅ Φ (p ; ν ) + 13.4 0.63e − 6 ν ) + 13.4 Σ cs m gleit m cs cs • ISO / TC60 Φ = 0.47 − 0.13 ⋅10−4 ⋅ p m − 0.4 ⋅10−3 ⋅ ν cS • external DLL
Parameters : R a ,S surface parameter pm
hertzian pressure
W'
specific line load
ν, η viscosity V surface velocity R contact radius
0, 6 ⋅ µ ODC =
1 8
S + 22 35 1 3
1 6
η0 ⋅ Vslide ⋅ VΣ ⋅ R
µ MIS = 0,325 ⋅ ( Vslide ⋅ VΣ ⋅ ν k )
µ BUK
µ TC6
1 2
W '⋅ S = 0,12 ⋅ R ⋅ V ⋅ η Σ 0
0,25
−0,25
3,17 ⋅ (10 )8 ⋅ W ' 50 = 0, 0127 ⋅ ⋅ log10 ⋅ η ⋅ V ⋅ V 2 50 − S 0 slide Σ
MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches
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Examples of Freewheel-Clutches Feeder-Unit
Overrunning clutch
Return stop
• material
• starter motor
• elevators • conveyor band
Firmenschrift Ringspann GmbH, Bad Homburg, 2012
MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches
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Idling and Switching of a Freewheel Clutch
Idling
Switching / Locking
ωouter
ωouter
ωinner
ωinner
MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches
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MBS Freewheel: Elements, Force Coupling, DOF Subsystem
Force Coupling
Z
Contact Sprag / Outer Race Sprag
Contact Sprag / Cage Torque-Momentum Sprag / Cage Contact Sprag / Inner Race
Outer Race Y Cage
X
DOF
Inner Race
rot. rot.
Main Model trs. y
rot. trs. z
MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches
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MBS Freewheel: Elements, Force Coupling, DOF • Single / multi area contact • Force coupling • 3D load distribution
• Eccentricity, misalignment • Substituted stiffness of outer race Contact Sprag / Outer Race
Z
Contact Sprag / Cage Torque-Momentum Sprag / Cage Contact Sprag / Inner Race
Sprag
Outer Race Y Cage
Inner Race
rot. rot.
X
trs. y
rot. trs. z
MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches
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UFEL - GUI • • • •
Create new or Modify existing contact Contact Marker From & To are based on Marker 96 Data Input
MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches
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UFEL Disc Model Disc Model • Discretisation of the contact in direction of width • Gap and overlapping at skew position and crowning b
R
b ϕ
ϕ
gap
gap and overlapping
overlapping
MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches
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MBS: Normal Force & Pressure Distribution Sprag Width [mm]
Angle
3 Switch Cycles
Contact Force [kN]
Sprag Width [mm]
Skewing of the Outer Race
3 Switch Cycles
Angle Angle Angle
Sprag Width [mm]
Intended Distribution
3 Switch Cycles
Crowned Sprag 3 Switch Cycles MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches
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Variation of Stiffness and Clearance
c2 = 2.5e8 ⋅ mN
c2 = 0.5 ⋅ c1
Clearance : 1
100
⋅ mm
c3 = 10 ⋅ c1 MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches
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Experimental Work
Frontside Backside
• Freewheel: o Sprags with strain gauges o at marked positions
MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches
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Experimental Work • Sprag with Strain Gauges at both sides
MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches
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Experimental Work • Calibration Unit • Continuous Force up to 10 kN
Sprag with strain gauge
Calibration Unit
MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches
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Flange Modification in Simulation & Experiment Asymmetric Load Distribution • Reduced outer diameter
78 mm
70 mm
MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches
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Flange Modification in Simulation & Experiment Asymmetric Load Distribution • Reduced outer diameter • Stiffening with a ring (SR) in the positions front, middle, rear • Configuration for test rig and FE-Analysis • Calculation of the substituted stiffness
70 mm, SR front
70 mm, SR middle
70 mm, SR back
Contact zone sprag / flange MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches
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Distributed Load in the Experiment Asymmetric Load Distribution • Force measurement with strain gauges (SG) at the sprag • Normal-Force in kN
6,52
5,05 5,19
SG back
6,12
SG front
5,96
5,75 70 mm, SR front
70 mm, SR middle
70 mm, SR back
MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches
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Freewheel with Lineload in the FE-Simulation
MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches
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Displacement Results from FE-Analysis Displacement at 10 kN line load, variation of outer flange diameter and place of the stiffning ring (SR)
Displacement in mm
SR back SR middle SR front without SR
front
middle
back Width in mm
MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches
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Comparison of Experiment and Simulation Asymmetric Load Distribution Stiffening ring in position front 3 contacts and substituded stiffness for flange Good agreement Difference 3-5%
Experiment Simulation back middle front
• • • •
Force in N
3 contacts
hinten back
mittig middle
vorne front
MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches
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Summary • Efficient methods and algorithms for modeling contact in MBS simulation with different model depths have been implemented and validated • 4 force models, 6 friction models and external DLL • Parameters influencing the contact behaviour include • Position, velocity, surface velocity, crowning, lubrication • Width discretisation of compliances is considered by disc model (direct stiffness) • Implementation into commercial MBS-Program Simpack was successfully validated • Marginal increase of calculation time • ca. 8% with 200 discs • 1-2% with Wijnant instead of Hertz • Additional Results • Postprocessing in Simpack • Data output in ASCII-Files (3D-representation, postprocessing) MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches
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Thanks to AiF
Schaeffler Technologies GmbH & Co. KG
FVA
IST
Simpack AK-Freiläufe
MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches
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Contact
Universität Kassel / University Kassel Institut für Antriebs- und Fahrzeugtechnik / Institute for Powertrain an Automotive Engineering Maschinenelemente und Tribologie / Chair for Machine Elements and Tribology Prof. Dr.-Ing. Adrian Rienäcker Mönchebergstr. 3 34125 Kassel T: +49 (0)561 804-2774 F: +49 (0)561 804-3727
[email protected]
MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches
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