CONTACT
윤재광
James Kennedy
Dear Ylg,
Here's some information about tied contacts and merged segments in LS-DYNA:
Tied contacts
Constraint-based contacts that connect a master segment to slave nodes. During initialization, slave nodes that meet certain criteria are moved to the master surface, eliminating gaps between the slave nodes and master segments. If a gap is visible when viewing the model, the node is not tied. LS-DYNA has several types of tied contacts, including those with offset, translational and rotational DOF, and failure.
Merged segments
Segments that can be combined into one, reducing the amount of disk space required. This can be done manually using the split and merge tools, which are accessible by clicking the Segment editing tools button within the segment being edited.
Sincerely,
James M. Kennedy
KBS2 Inc.
June 3, 2024
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James Kennedy
Dear Yjg,
Trouble-shooting: Tied contact doesn't appear to work
Look for the word "Warning" in your message file to see if there are any messages about slave nodes not being tied. If slave nodes are too far away from the master surface, the slaves will not be tied. This threshold distance is defined in Remark 2 on p.
7.42 of the 971 User's Manual. Note that by setting the slave and/or master contact thickness to a negative value, the threshold distance can be manually controlled.
Unfortunately, there's no convenient way to display unconstrained nodes. A suggestion -- use the unix command grep to get a listing of unconstrained nodes, e.g.,
grep "slave node ID" d3hsp >list
Then edit this listing to make a node set via *SET_NODE_COLUMN. Insert this node set into your input deck and read the deck into LS-PrePost in order to view the node set.
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Examples
https://lsdyna.ansys.com/tied-1/
https://www.dynaexamples.com/introduction/examples-manual/contact/tied-2
Sincerely,
James M. Kennedy
KBS2 Inc.
June 4, 2024
From:
윤재광 [mailto:yjg...@gnu.ac.kr]
Sent: Tuesday, June 04, 2024 1:36 AM
To: James Kennedy <j...@kbs2.com>
Cc: LS-DYNA2 <ls-d...@googlegroups.com>
Subject: Re: [LS-DYNA2] CONTACT
Thanks for the reply. There are many CONTACT_TIED conditions. I am using CONTACT_TIED_NODES_TO_SURFACE. However, the model disappears during analysis. Could you help me?
2024년 6월 4일 (화) 오전 12:17, James Kennedy <j...@kbs2.com>님이 작성:
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