Simulation Separation Contacts Not Working

[bodhe]

I am trying to simulate a static load on a geometry with separation contacts. Sometimes the separation contact works - when the faces touch, they slide relative to each other without penetration. sometimes, nothing happens as if the contact isn't there. I have tried messing with the activation distance and nothing works. I am working through different designs and this is a consistent problem across a variety of different contact situations. It is incredibly frustrating and has me really questioning our investment in Fusion. 

[henderh]

Hi @bodhe,

I presume you have the Actual deformation active in the screenshots, and not the default Adjusted scale?

If it is the Actual deformation showing the penetration, could you share the study that is having the contact issue?

File > Export... and attach it here, or share the web link where we can download the F3d.

Thank you,

[bodhe]

Here is the exported file. yes that was showing actual deformation. interestingly, exaggerated deformation actually shows less than actual. 

[henderh · Accepted solution]

Hi @bodhe,

The correct contact behavior can be achieved by:

1. Using the Nonlinear Static Stress study type
2. Setting the Max. Activation Distance to 1.0mm

The the NLSS study type is better able to handle this type of simulation, when faces are initially separate, then come into contact with each other, and begin sliding.

In general, the linear static stress study type isn't well suited to handle the situation of a large deformations, large gap, and uses linear contact.

The Max. AD size of 1mm was chosen due to the gap size of 0.75mm, plus extra to "span the gap". 

Hope this helps!

[bodhe]

Ok, that worked. Really a bummer that you have to pay $1500/year (triple the base cost) to get this to work. Feel like I am being nickeled and dimed. 

Can you elaborate on the activation distance? What does that mean? Does automatic activation distance work?

[henderh]

The solver has to know which faces may come into contact before the solve is started, this is controlled by the Max. Activation Distance. A support article is available that goes into detail for this topic. It also applies to Fusion:

• Understanding maximum activation distance and contact type in a Simulation

We offer a Flex payment method which is cost-effective for occasional use of simulation.

• Autodesk Flex Pay as you go for occasional product use.  

Best regards,