Plastic snap

Using SimScale Solid Mechanics / FEA
4

Hey @fbernhardt!

I must say good work there. You have set it up really well but there are only few problems.

  1. Your displacement value is making the part to move in positive z direction i.e. away from the other. Therefore, just make the value negative and it will move towards the other part.

  2. Your symmetry boundary condition is not properly defined. You have to select the two outer faces. Please see the figure below:

symmetry-problem.png1640×1081 290 KB

  1. You can switch equation solver to MUMPS under Numerics. And also change number of computing cores to 8 in order to make simulation faster.

Next once you are done with this, I would recommend you to duplicate the mesh and create a refinements on the contacting faces to have better results.

Hope this helps. If you have any other question/s, feel free to ask.

Best,
Ahmed

3 Likes
5

Hey @fbernhardt! I also just figured out that the displacement is too high. Your distance to fully snap it is just 0.0038 m to be exact. You can thus use 0.004 m to make it snap properly. 0.014 is way too high.

1 Like
6

Thanks for taking a look!
So to get the moving right, just add the minus here?

7

yup that’s right! :thumbsup:

8

So after some hours of computing this message comes:

The computation was canceled either by a user request or due to the
maximum execution time being exceeded. Trying to recover intermediate
results.

Any ideas which settings I could change?

9

Hi @fbernhardt,

increase the Maximum runtime [s] in Simulation Control.

See also: Maximum calculation time exceeded

Hope that helps!

Jousef

10

Hi @fbernhardt!

Don’t increase maximum runtime since I saw your solution is diverging. The problem is in contact. I am also trying and will get back to you once I have a solution.

Best,
Ahmed

1 Like
11

Thanks for jumping in @ahmedhussain18!

That’s what I did not notice. Thank you for mentioning! :slight_smile:

Best,

Jousef

12

How you insert the properties of PC+ABC ?

13

Hi @daniel11 : So PC+ABS ist not available in the material data base. So i chose only ABS for the first attempt.

1 Like
14

You build the files in Onshape ?

15

Hi @daniel11 : No, I used Solid Works.

1 Like
16

Hello @ahmedhussain18 : We’re you able to find out the problem?
kind regards

17

Hey @fbernhardt!

Yes! so far I am able to perform until the point it is about to snap properly. After which the simulation diverged every time. I will probably try to do it with a little friction if it may help the immediate sliding to occur less. But this may include more complexities. Below is the figure of the final step of the performed simulation:

screenshot.png1024×768 100 KB

Please find the link to the project here: SimScale

You can of course copy the project and try to solve it further.

Best,
Ahmed

18

sir, can you explain about the formula in brief?

19

Hi @Omer!

Formulas like these are time-dependent meaning that they are incrementally increased over time.

Example: -0.0036t means that at the last time step (which is 1) the displacement “condition” in z-direction of -0.0036[m] will be fulfilled starting at 0 displacement at the initial time t=0. In the next step you will have -0.00360.05[m] and so on.

Hint: Initial time step length [s] is defined in the “Simulation Control” option in the Simulation Designer.

Does that make sense?

Cheers,
Jousef

20

thanks, Josef.
here 0.05 is in auto time stepping?
secondly, in static analysis, is run time different from the time “t” mentioned above?

21

Hi @Omer,

yes it is. The runtime and time stepping time are quite different. That makes sense as the runtime would not set a distinct BC as it varies from run to run.

Best,
Jousef

22

so from above the distance would increase from 0 to -0.0036 in 1 sec.is my statement correct?

23

Exactly @Omer!