Learning Forum

[Vikram33]

I'm modelling spur gear tooth wear using Archard wear model. I have set frictional contact and wear model in accordance with Ansys help guide:

K=1e-8

H=840

m=1

n=1

TB,WEAR,1,,,ARCD

TBFIELD, TIME,0

TBDATA,1,K,H,m,n

TBFIELD, TIME,1.5

TBDATA,1,K,H,m,n

But the user-defined result, NMISC189, for wear volume gives zero value. Can someone help me with this?

[mrife]

Which version of Mechanical APDL are you using? The wear volume was not always available in nmisc189, but in the nlhist listing, so I think you might have mixed the version you are using and the version of the help.
Mike

[Vikram33]

thanks for your response. I'm using Ansys 2020 R2 and I used the same version of help. Anyways, I got the results in nmisc189 by changing the wear definition to 'TB,WEAR,cid,,,ARCD' and also changing the contact behaviour to 'asymmetric' and detection method to 'nodal-normal to target' (not sure which one helped!).
Another thing is that I could not find any units specified for nmisc189 in Ansys help or elsewhere. That is, I'm not completely sure what VWEAR represents - is it the rate of volume wear or total volume wear or something else. Can you help me with that?

[Vikram33]

Also, I got the values only in the user-defined result CONTNMISC189 and not in NMISC189. What's the difference between the two?

[mrife]

Not to be a jerk, but Ansys Inc does not have a product called "Ansys". You seem to be using Workbench Mechanical 2020 R2. Mechanical APDL is the solver WB Mechanical uses, and is itself a fully featured FEA program.
Now, WB Mechanical is not quite Mechanical APDL so take care when trying to apply 'stuff' from one to the other. The contact Commands Objects in WB Mechanical will locally store the contact ID number as CID and the Target ID number as TID. Whereas that help guide was a generic example. Also the example shows the form of introducing time dependence to the Archard variables definition...but does not actually change the values.
You will need to dig into the WB Mechanical help, results section, but it does implement CONTNMISCnnn style to retrieve NMISC data for contact elements. Which extrapolates the single element value to the corner nodes.
VWEAR is the volume of wear...please see the result section of the Contact174 help entry (MAPDL Help -> Element Reference).
Mike

[Vikram33]

Thanks for the explanation

[averageMechGirl98]

I am having similar problems in getting the wear volume in results. I am not good in using commands tbh.
Can you please help me out , I am an engineering student doing online classes in Chennai.
Thanks a bunch!!