Recurring Meeting of Cleveland Clinic - University of Utah
Date: June 8, 2016
Time: 2:00 PM EST
Means: Conference call
Attendees:
- Ahmet Erdemir (Cleveland Clinic)
- Jeff Weiss (University of Utah)
- Steve Maas (University of Utah)
Agenda:
- Recap of action items from past meetings.
- Deformable springs with contact.
- Shell element formulations.
- Discrete element analysis.
- Decide action items for next meeting.
- Other.
Immediate Action Items:
- Cleveland Clinic (Ahmet)
- E-mail Jason Halloran to discuss spring elements with Steve.
- University of Utah (Jeff)
Get FEBio users in touch with Ahmet, if help to use SimTk.org is needed.
- University of Utah (Steve)
- Explore generalization of wrapping spring elements feature for nonlinearity and for model setup.
- Follow up with Gerard Ateshian about formulations for shell elements on solid elements.
Notes:
- Recap of action items from past meetings.
- Action items were mostly related to agenda of the meeting; see notes below.
- Deformable springs with contact.
- Steve implemented springs elements that can wrap around objects through contact. He had some convergence issues. In following, he identified the potential problem to be based on setting up the assembled stiffness matrix for prescribed displacement. Steve thought that he can resolve this issue.
- Jeff asked about a particular knee model that can be used as example for representation of ligaments with springs wrapping around bones. Ahmet noted that the model they used for the in situ strain manuscript can serve well. Yet, he also asked for the possibility to setup in situ strain (or slack length) for deformable springs. Another question was related to nonlinear springs. Current implementation is limited to linear formulation. Steve may need to calculate the whole length of the structure modeled as a series of springs and may have to implement features to distribute an overall stiffness property to a series of springs. Ahmet recommended him to chat with Jason Halloran; he will e-mail Jason and Steve to start the discussion.
- Shell element formulations.
- For shell elements, Gerard Ateshian came up with an idea to setup an initial formulation to couple shell elements to solid elements. Steve will follow up with Gerard.
- Discrete element analysis.
- Discrete element analysis will be explored if and when the group can allocate time for it.
- Decide action items for next meeting.
- See Immediate Action Items above.
- Other.