IBBM 2017

quad8 unrecognized for sliding contact
issueid=750 06-28-2016 01:03 PM
Junior Member
quad8 unrecognized for sliding contact

In 2.5 quad8 elements give an unrecognized tag error when used in sliding contact. I checked that the other shell elements all worked, only the quad8 gives the error. I haven't check any other types of contact.
Issue Details
Issue Number 750
Project FEBio
Category Unknown
Status Fixed
Priority 5 - Medium
Affected Version Unknown
Fixed Version (none)
Users able to reproduce bug 0
Users unable to reproduce bug 0
Assigned Users (none)
Tags (none)




06-28-2016 06:58 PM
Moderator
Hi Steve,

Would you please attach a sample file? I can't reproduce your problem with the information provided.

Thanks,

Gerard

06-29-2016 09:16 AM
Junior Member
Sure. I attached two feb files. Each is the same simulation. One uses quad4 elements and the other uses quad8 elements. You should see the error for the quad8 simulation. The quad4 should run successfully.

06-30-2016 02:24 AM
Moderator
Hi Steve,

Thanks for attaching these examples. I was able to confirm your report. It turns out that the issue is specific to "sliding_with_gaps", which uses nodal integration, whereas the other contact algorithms use Gauss integration. So far we have only implemented quad8 and quad9 elements with Gauss integration. We can add nodal integration versions of these elements in the next release. In the meantime you can try one of the other sliding contact algorithms, such as "facet-to-facet sliding".

Best,

Gerard

07-02-2016 12:58 PM
Moderator
I have updated the code to include quad8 and quad9 elements with nodal integration. This update will be available in the next release (2.6).

Best,

Gerard

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