Learning Forum

[Dalyan11]

[Fernando Torres]

Hi Dalyan,
Please check if the target's body (plate) is set as flexible and apply a suitable material model like johnson cook if the target is metallic, mooney rivlin if it's rubber etc by going to Engineering Data. This could be the partial answer to what you are looking for. Thanks!

[Dalyan11]

Thank you for responding but didn't work

[peteroznewman]

Please use File Archive to create a .wbpz file and attach that to your reply. I will take a look.

[Dalyan11]

[Dalyan11]

Please what is your ansys version to export the file for that?

[peteroznewman]

I am using ANSYS 2021 R2. You don't get a choice when creating the Archive.

[Dalyan11]

Ok, also I'm using this version

[peteroznewman]

I am offering to look at your model to try to resolve the issue. There are two things you need to do if you want to take me up on this offer.
Save a .wbpz file
Use the paper clip icon at the bottom of your reply and attach the .wbpz file.

[Dalyan11]

[peteroznewman]

First observation: There is a 0.0032 m gap between the bullet and the plate. This is a waste of time solving the motion to close the gap. It is best to put the tip tangent to the plate in CAD.
Second observation: The end time is 6.8e-6 seconds and the initial velocity is 450 m/s so the distance travelled in that time is 0.00306 m which is less than the gap.

The time must be long enough for the bullet to get to the back of the plate or 0.02 m to that would be 4.44e-5 s

[Dalyan11]

Thank you for your help dear, if you help me for mashing also i will be so thankful.

[peteroznewman]

What is mashing?

[Dalyan11]

Sorry y meshing not mashing

[peteroznewman]

What is wrong with the mesh? Why do you want to change it?

[Dalyan11]

Because the automatic meshing is not accurate enough to gives a good results

[Dalyan11]

Because the graphs is not accurate so i believe that the mesh that affects it

[peteroznewman]

What results are you looking at?
How do those results change with element size?

[Dalyan11]

I want a regular smooth graph, but that graph doesn't give me that result, for example the velocity and kinatic energy bo the bullet decrease and increase again and decrease, so that result it is not acceptable in real situation how the energy increase after it is decreased ?

[peteroznewman]

Explicit Dynamics solutions are well known to be noisy and often require filtering to obtain smooth curves.
Some of the noise comes from the large element size and using smaller elements will reduce the amount of noise in the results. Have you tried reducing the element size by a factor of 2? After you do that, reduce the element size by a factor of 2 again for a total of a factor of 4 from the original mesh. Is the raw data on the energy becoming smoother? Do you know how to low pass filter data?