Altair RISE

A program to recognize and reward our most engaged community members

Nominate Yourself Now!

Setting up a TIE contact

Hello,

Could anybody please provide me a documentation or a tutorial (know-how, what should be considered etc.) how to set up a contact between 2 non-matching meshes in HyperMesh properly? The regions will not touch each other, I just want to transfer a load between them. I heard that a TIE contact is used in this case.

Thanks.

Find more posts tagged with

English

HyperMesh

Accepted answers

All comments

Altair Forum User

what solver do you use?

in optistruct is possible to do tie contact automatic=)

tools->contact brouser->entities field mouse right button->autocontact->property type 'freeze' for tie

Altair Forum User

Thank you @Mrt for answering me.
I am able to set up the TIE contact now however I would like to ask you if there is any documentation in English which type of contact in which situation should be used and the properties of the contact. Also I would like to know if the TIE contact does add stiffness to the structure. Because if it does, it's undesirable. Could you please give me an advice/recommendation?

Pranav Hari

Hi Zdeny

Tie contact will add stiffness to the structure but the relative displacement is zero. Tie is similar to FREEZE contact in OptiStruct. Which means each slave node will have the same motion as the node of the master through out the simulation.

Altair Forum User

Hello @Pranav Hari

thank you for your answer but what doest this mean to me? Relative displacement is zero means that slave nodes will move exactly the same as master nodes, right? For example, I have a long cantilever beam fixed at the end and with force applied on the other end. I will cut it to thirds. I will remove the middle part of it and set a TIE contact instead. Will the deformation be continuous? Are there any limitations of using TIE contact?

Pranav Hari

Hello Zdeny

Relative displacement is zero means that slave nodes will move exactly the same as master nodes, right?

Yes

Tie contacts are mostly used to connect 2 meshes of different densities, shell mesh to solid mesh and to define contact between 2 meshes. Cantilever is not a good example as when you apply a load at one end after constraining the other end, it will undergo bending. At the same time a shear force will also develop between the layers. So if you use a tie contact you wont get a reasonable result, since the relative displacement and forces on the point where tie contact is defined will be zero.

It depends on what you are modelling. If the surfaces are a tight fit to each other which will not change during the simulation you should be using TIE. However, if the surfaces are lying on each other and the contact area is likely to change during the simulation, you should not use Tie contact

Think of how the problem would be set up in real life test conditions and then you have to set up the model based on that.

Altair Forum User

And isn't there a problem when I use TIE contact to connect shell and solid elements? Because solid elements does not transfer rotation and shell does.

I've made an example, please see the attached pictures. I want to connect 2 solid meshes using a TIE contact. But as you can see, the displacement and also the stre ss is different. Could you please tell me if this is a problem or where are the limitations?

<?xml version="1.0" encoding="UTF-8"?>

Pranav Hari

Hi Zdeny

You can use Tie contact to connect shell mesh and solid mesh.

Can you please share this example model