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

2

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

3

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

4

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

5

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

6

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

7

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

8

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

9

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

11

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

12

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

13

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

14

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

15

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

16

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

17

Experimental Work • Sprag with Strain Gauges at both sides

MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches

18

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

19

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

20

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

21

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

22

Freewheel with Lineload in the FE-Simulation

MBS Simulation Techniques to Determine Spatial Load Distributions and Torque Build-Up for Freewheel Clutches

23

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

24

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

25

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

26

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

27

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

28