## General Mechanical

Topics relate to Mechanical Enterprise, Motion, Additive Print and more

#### Isoparametric elements

• Dor
Subscriber

Is the "free meshing" makes Isoparametric elements by default? If not, then what function does this?

Thanks

• peteroznewman
Subscriber
Under the Mesh Details, when you set Element Order to Linear, you will get Isoparametric elements.
• Dor
Subscriber

Thank you peter You know what my project is.
I'm pretty sure that in my case, most of the elements are quadraticand not linear, so most of the elements are not isoparametric?

And one more quation:
I think my simulations are non-linear. In these non-linear problems the stiffness matrix is very dynamic, chanes. However I didn't entered to the engineering data anything about that (just the Young's modulus and similiar mechanical properties). So the software knows to change and to calculate the stiffness matrix by itself?
• peteroznewman
Subscriber
In your last model I saw, you left the Element Order Program Controlled, which means it go the quadratic elements. You can easily change to Linear and see what happens. Since your geometry is all curved, I think quadratic may be better, but maybe because you have a lot of contact, more smaller linear elements would be better. I don't know.
Yes, you have a nonlinear model because you have frictional contact.
Yes, the software creates the stiffness matrix for you automatically.
• Dor
Subscriber
Since your geometry is all curved, I think quadratic may be better
I'm trying to understend why. Because this way, the mid-side nodes enable the curved geometry while rolling?

By the way, I defined the environment to be with a certain pressure. When the film twists and changes, some areas of the film lift, roll and detach contact from the surface of the bowl. The software applies the pressure in these areas?

Thanks again Peter and sorry about my broken English
• peteroznewman
Subscriber
That figure is not correct for ANSYS. There is a midside node, but the edges that go through the three nodes are curved, not straight lines so they look more like the circular profile.
The pressure is applied to all the surface independent on whether the surface is making contact or not.

• Dor
Subscriber
In your last model I saw
I would also like to make sure: My model-gride type considered to be 2D or 3D? I am confused
Seems like 2D solid is the answer- in my case the model is very thin, eventough it's actually 3D model.

• peteroznewman
Subscriber
Your model is a 3-D SHELL because you have a section of an approximately spherical surface and you are assigning a thickness property to the shell elements, that thickness being very thin.
2-D SOLIDS have to be planar.
• Dor
Subscriber
Thank you very much :)