Results 1 to 3 of 3

Thread: "Hyper-elastic material may become unstable" message for Mooney-Rivlin model

  1. #1

    "Hyper-elastic material may become unstable" message for Mooney-Rivlin model

    Hi All,

    I am trying to use my experimental data for vulcanized natural rubber for some finite element simulation in ANSYS, and noticed that the closest fit is given by Mooney-Rivlin. But unfortunately, this material model gives the warning mentioned in the subject prior to solving, and the process terminates with "error in element formulation".

    Other material models like Neo-Hookean and Ogden don't seem to be providing a good fit with the experimental stress-strain curve, but there's no such warning or element formulation error for those.

    I'm simply using a rectangular area with Plane Stress w/Thk element real constant specified, plus the aforementioned curve fitting of my experimental curve.

    Please advise.


  2. #2
    Join Date
    Boston, USA
    Can you show figures with the experimental stress-strain curve(s) that you have?

    Jorgen Bergstrom, Ph.D.
    PolymerFEM Administrator

  3. #3
    Hi Jorgen,

    I was able to curve-fit by unchecking the "Use Normalized Error" checkbox in the curve-ftting dialog in ANSYS. I'm not exactly sure what purpose it serves, but the fits are good now.

    Currently I don't have access to the images. I will share as soon as availble.

    Many thanks!

Similar Threads

  1. A question about the output vaviable "rotation tensor R" in ABAQUS
    By rasier in forum Finite Element Modeling
    Replies: 2
    Last Post: 2012-02-29, 00:18
  2. The difference between "mesh on part" & "Mesh on Instance" In ABAQUS
    By Geotech2011_1 in forum Finite Element Modeling
    Replies: 2
    Last Post: 2012-01-14, 08:28
  3. blank lines automatically disappearing in "edit keywords"
    By jimstazinsky in forum Finite Element Modeling
    Replies: 3
    Last Post: 2010-06-19, 19:38
  4. Abaqus error message"'LINK' is not recognized"
    By pateno in forum Computer Software
    Replies: 7
    Last Post: 2010-03-17, 06:47
  5. Replies: 3
    Last Post: 2009-04-26, 19:32

Tags for this Thread


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts