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  * See discussion on in situ strain problem.
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  * Steve implemented the in-situ strain test problem in FEBIo.
   * A two-step analysis was set up.
   * In the first step in-situ stretch is applied (for different levels of stretch)
   * In the next step a saw tooth prescribed displacement was applied on the free end of the beam (geometry : 1 by 10 mm mesh) and the stress-displacement curves were provided.
   * Ahmet made an observation regarding the constitutive model (stress is not zeroed in the model).
   * Jeff pointed out that the fiber stress is zeroed out but in these results the compression stress is due to the matrix and not fibers, this is due to coefficient values i.e the selected material model.		   * Steve implemented the in situ strain test problem in FEBIo. A two-step analysis was set up. In the first step in situ stretch is applied (for different levels of stretch). In the next step a saw tooth prescribed displacement was applied on the free end of the beam (of geometry 1 x 10 mm mesh) and the stress-displacement curves were provided.
   * Ahmet made an observation regarding the constitutive model, i.e., stress was not zero at expected levels of zero force length. Jeff pointed out that the fiber stress would be zero but in these results the compression stress is due to the matrix and not fibers. It is possible that this is due to coefficient values selected for this test problem. More physiological material properties will be incorporated to see if this issue will be resolved.
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  * A new version of FEBio will be released in January 2014.
   * A new file format is implemented.
   * Elements are organized the way it is done in Abaqus. Element type can be defined and given a name to define the element sets.
   * Similar implementation will be done for surface and node sets and a case study will be developed for implementation and testing.
   * An element can not be defined in two different sets currently.
   * CCF team will provide an example and test problem to test solution and extraction of information for different sets (in the output file).
   * Overlapping may not be a concern for element sets but may be an issue in surface and note sets.
  * CCF engineers might attend the FEBio summer course. 		  * A new version of FEBio will be released in January 2014. A new file format is implemented.
  * Work on definition of sets has started. Elements are organized in a similar way as in Abaqus (Simulia). Name of the element set can be provided along with the element definition. A similar implementation will be done for surface and node sets. A case study is needed for implementation and testing. Currently an element cannot be defined in two different sets. Lack of incorporating elements in different sets may not be a concern but this may be an issue for surface and node sets.
  * FEBio team is organizing a training workshop in the summer of 2014. Cleveland Clinic engineers might attend to this summer course.

Recurring Meeting of Cleveland Clinic - University of Utah

Date: December 20, 2013

Time: 3:00 PM EST

Means: Conference call

Attendees:

  1. Ahmet Erdemir (Cleveland Clinic)
  2. Jason Halloran (Cleveland Clinic)
  3. Snehal Chokhandre (Cleveland Clinic)
  4. Jeff Weiss (University of Utah)
  5. Steve Maas (University of Utah)
  6. Ben Ellis (University of Utah)

Agenda:

  1. Discuss assigned task progress.
  2. Discuss implementation of in situ strain test problem.
  3. Decide tasks for next meeting.
  4. Other.

Immediate Action Items:

  • Cleveland Clinic (Jason and Ahmet)
    • Prepare a test problem representative of the use of element, node, and surface sets.
  • University of Utah (Steve and Ben)
    • Read and review the reference on connector elements provided by Jason for further discussion.

Notes:

  1. Discussed assigned task progress.
    • See discussion on in situ strain problem.
  2. Discuss implementation of in situ strain test problem.
    • Steve implemented the in situ strain test problem in FEBIo. A two-step analysis was set up. In the first step in situ stretch is applied (for different levels of stretch). In the next step a saw tooth prescribed displacement was applied on the free end of the beam (of geometry 1 x 10 mm mesh) and the stress-displacement curves were provided.
      • Ahmet made an observation regarding the constitutive model, i.e., stress was not zero at expected levels of zero force length. Jeff pointed out that the fiber stress would be zero but in these results the compression stress is due to the matrix and not fibers. It is possible that this is due to coefficient values selected for this test problem. More physiological material properties will be incorporated to see if this issue will be resolved.
  3. Decide tasks for next meeting.
    • See Immediate Action Items above.
  4. Other.
    • A new version of FEBio will be released in January 2014. A new file format is implemented.
    • Work on definition of sets has started. Elements are organized in a similar way as in Abaqus (Simulia). Name of the element set can be provided along with the element definition. A similar implementation will be done for surface and node sets. A case study is needed for implementation and testing. Currently an element cannot be defined in two different sets. Lack of incorporating elements in different sets may not be a concern but this may be an issue for surface and node sets.
    • FEBio team is organizing a training workshop in the summer of 2014. Cleveland Clinic engineers might attend to this summer course.

RecurringMeetings/2013-12-20 (last edited 2016-05-04 22:09:49 by localhost)