Dear community, I need your support about my simulation.

I want to analyse the contact between a rolling wheel and rail as it is shown in the picture using ANSYS APDL but my results are not as was expected like specially the repartition of the stick and slip zones which is given in APDL by contact status. i don't know why there is no stick zone in the contact patch? the contact status indicates always that the wheel is in sliding status even when the wheel is not moving. Please let me know if you have any suggestions or corrections to my issue 🙏🏻🙏🏻🙏🏻.

To simulate the rolling motion of a loaded wheel, I defined three steps:

-step1: the bottom side of the rail is fixed

-step2: the contact is established by moving down the wheel by 0.006m

- step3: the load (FZ=-75000N) is applied to the pilot node

- step4 : translation velocity (Vx=50km/h) and angular velocity (Omgy)and are applied at the pilot node.

Here is the code corresponding to these load steps:

/SOLU

ANTYPE,4

nlgeom,on

TRNOPT,FULL,,,,,NMK

TINTP,HISP!GAMMA = 0.005

KBC,0

RESCONTROL,,NONE,None

autots,off

OUTRES,ALL,ALL

!First load step: Rim-mounting

Time,0.001

DELTIM,dt,dt,dt

TIMINT,off

! Constrain the rail base

asel,s,area,,42

da,all,all

Allsel,all

Solve

!Second load step: Establish the Contact Between the wheel and the Rail

Time,0.002

DELTIM,dt,dt,dt

TIMINT,off

!fix the pilot node in all directions

D,NODENUMBER+1,all

! Move the wheel toward the rail

D,NODENUMBER+1,uz,-0.006

Allsel

Solve

!Third load step: Applying a Vehicle Load to the 3D rail Model

Time,0.002+tfch

DELTIM,dt,dt,dt

TIMINT,off

!Delete the previously applied displacement loading

ddel,NODENUMBER+1 ,uz,,,on

!Apply the vehicle load on the pilot node

f,NODENUMBER+1 ,FZ,-Cn

Allsel

Solve

!step2 rolling

!inserting speed values

Time,0.002+tfacc

DELTIM,dt,dt,dt

TIMINT,on

D,NODENUMBER+1,omgy,Wr

D,NODENUMBER+1,velx,V

Allsel

SOLVE

!pick up solution stage d=115mm

Time,0.002+tfres

DELTIM,dt,dt,dt

TIMINT,on

Allsel

SOLVE