Setting contact between parts

[Anonymous]

Hi everyone,

I am confused about setting up the contact between different parts of the assembly. If we do not manually set the contact type, will the program automatically compute the contact type while simulation and set the contact based on the 'default contact type'... Or, we always have to  'manually select the contact type'... 

Also, if in my assembly there are, say, 2 parts which are  not touching each other in any way, but may interact due to deflection because of applied load, then do I have to intentionally set the contact type (say surface to surface contact) between the probably interacting surfaces of those parts... 

Thanks

Siddharth

[Andrew.Sartorelli]

Hi Siddharth,

When initially defining contact between two surfaces for example you will be able to select from Bonded, Welded, Free Contact, and Surface Contact. Once you have initially defined a contact you are able change the contact type by right clicking the contact in tree view. Similarly, you can change the default contact type for the simulation by right clicking the Contact header in the FEA Editor tab of the tree view.

If you are performing a non-linear analysis then you can select Surface Contact for parts that are initially separated but you expect come in contact during the simulation.

You can learn more about the contact types and applications by visiting Simulation Mechanical 2014 Help and then searching contact. Here are some direct-links to some relevant articles Types of Contact and Contact Pairs Overview.

[AstroJohnPE · Accepted solution]

Hi Siddharth,

You are correct: all parts of the assembly received the type of contact set in the "Default :". Of course, contact pairs that you create supercede the default.

For linear stress analysis, which is based on small displacement, contact between parts is only created if the parts are initially "in contact". In your case where parts may contact due to the displacement, this would be considered large displacement. For this case, you should use the Nonlinear > MES analysis type and set surface contact between the surfaces that will come into contact. (Of course, if you do not know whether the displacement is enough to cause contact, perform a linear analysis first. This analysis type is much faster, and it will show whether an MES analysis is needed or not.

[Anonymous]

Thank you Andrew and John for clearing my confusion.

Regards,
Siddharth