Learning Forum

[mostafa-nageeb]

Hello everyone,

I am using the implicit transient solver to solve a motion of a ball into and out of a retaining spring. The APDL command and the project are shown below

[mostafa-nageeb]

According to this thread
some user-defined expressions can be used to define the wear in a certain direction.

contnmisc172 for wearX, contnmisc176 for WearY and contnmisc180 for wearZ

I have been reading the documentation as to where these numbers come from, but I could not find it. Could you help?

[Sean Harvey]

Here are some pointers.
To change, the contact/target, you first go to the contact pair and set the behavior to be asymmetric.
Then you right click on the contact pair and you can pick flip contact/target to switch.
You will see the wear on the contact.
You can setup symmetric contact and two wear models, but that is less common, especially for a pair of materials where one is softer.
It is not a requirement the 2nd body is rigid.
For the wear model, you can specify H based on the material hardness. Then what you set for K, m, n can be established if you have any measured data onwear. I realize you probably do not but if you can find any literature that reports, you can tune this model. Then once you have that you can use the model to be predictive, but most likely you need this model to first be calibrated with some physical test data.
For user defined results likeweary node I,weary node jwearx andwearz too. These report thewear(length unit) in the indicated direction at the I,j,k,l nodes of a 4 noded element (corner nodes).So when you look at these plots you can see how the pad iswearing.It may seem a bit odd that we have to look at I,j,k,l independently, but you look at all 4 of them to get an idea of the patterns and amount ofwear.Thiswearnumber times the area of the element summed over all the elements of the brake pad face (that has contact) up will equal the volume loss due towearin solution information. So againweary is just the amount ofwearin the y direction The x,y,z are the global directions so keep that in mind.
Please see if this helps.

Regards Sean

[mostafa-nageeb]

Such a perfect answer! Thank you very much for the clear explanation

[Sean Harvey]

Hello, Oh so nice to hear and help. Thank you.

Regards Sean