Learning Forum

[hyang380]

Hi,

I'm using ANSYS Workbench 17.1. I'm doing a simulation with two bodies rubbing (cylinder/block, plane-strain) with a rigid top to introduce force.

I used the command to introduce wear between the two bodies:

TB,WEAR,cid,,,ARCD
TBDATA,1,1e-2,2.55e9,1,1
TBDATA,6,nx,ny,nz

It is asymmetric contact with Detection Method: Nodal-Normal From Contact

 

Here is my problem:

 

I need to introduce mesh nonlinear adaptive procedure to remesh during wear. I used the NLADAPTIVE command:

nladaptive,wearbody,add,contact,wear,0.5

nladaptive,wearbody,on,,,5,1,17

 

The component "wearbody" is the body of the block (Contact body) defined by name selection.

 

However, I didn't notice any remeshing during the wear procedure, where I did notice 50% wear volume off of the contact element.

 

Can anyone help me out?

 

Thanks,

 

Huaidong 

 

 

[Bhargava Sista]

Huaidong,

What order (linear or quadratic) elements are you using to mesh the flexible part? I need to check but it's possible that NLAD is not supported for quadratic elements. Look into the solver.out file for any Warnings or Notes indicating that NLAD has been disabled. Also, I don't remember if NLAD was supported on distributed solver in 17.x so that is another thing to check, turn off the distributed solver for now.

Also, check the frequency at which the re-meshing criteria is checked. Currently, it is being checked every 5th sub-step between the start time (1) and end time (17). You may want to change the frequency to 1 (every substep) so you don't miss the points where the wear goes beyond 50%).

[jj77]

hyang380,

there is someone else that is trying to simulate wear, and he is a bit stuck, he does not know how to view/contour the wear of the contact element (NMISC181 I think, but then again I am not sure since I have never done this ??), in workbench.

 

You seem to have overcome that if you could share how you did that would help him and others, and I am sure they would appreciate that a lot.

[hyang380]

Hi bsista,

 

Thanks for your help. I tried both the linear and quadratic elements. And I changed the frequency to every 1 sub-step, and I closed Distributed solver. However, I still couldn't make it work. 

 

I thought these two things may be wrong.

 

1.In the command:"nladaptive,wearbody,add,contact,wear,0.5"

I defined the "wearbody" by name selection for the geometry of block (or cylinder, or both). Is it correct? (I mean should I picked just the geometry, or is there a way to pick the contact element?)

2.Does the adaptive mesh for wear support for 2D study, or does it support for version 17.1?

 

For the solver.out file, I do see the description below:

Thanks

[hyang380]

jj77,

 

I made it work using :

• 
  

  The target surface is modeled with either TARGE169 or TARGE170 (for 2-D and 3-D, respectively).

  
  


• 
  

  The contact surface is modeled with elements CONTA171, CONTA172, CONTA173, and CONTA174.

  
  

I'm not familiar with NMISC181. But I'm willing to help if he has questions.

 

The basic idea is to input command after "Static Structural":

NLHIST, Key, Name, Item, Comp, NODE, ELEM, SHELL, LAYER, STOP_VALUE, STOP_COND

 

For example:

NLHIST,PAIR,WEARVOLUME,CONT,WEAR,4,,,,,,


Here, my contact set id is 4

 

Thanks, 

[Bhargava Sista]

Ah, there's the problem! The wear criterion is defined for the contact elements (not the underlying solid elements) so the component in NLAD command must be the contact elements (cid), not a named selection for the geometry (body). Continue using linear elements and turn off the distributed solver for now and try again.

[hyang380]

I did want to use the contact elements to be the component. However, I don't know what is the contact elements name. I used "cid", while it doesn't work. It keeps receiving:

*** WARNING ***                         CP =       2.543   TIME= 18:03:58
 No component with name= CID is defined.  The NLADAPTIVE command is    
 ignored.          

 

[hyang380]

I made it by select the contact pair:

ESEL,S,REAL,,CID

nladaptive,all,add,contact,wear,0.5

nladaptive,all,on,,,1,1,17 

You saved my life!

Thanks a lot!

[suddtu]

Hi hyang380,

ESEL,S,REAL,,CID

nladaptive,all,add,contact,wear,0.5

nladaptive,all,on,,,1,1,17 

I used similar code for calculating wear in rail wheel assembly and I am struggling to get post processing visualisation. Also, I am not sure if ansys is reading the archard wear command.

Please Help !!