simtk.org

For Open Knee v1.0.1, it was reported that Preview may have some problems importing the tf_joint.feb file.
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Here are the errors that I get when I import the tf_joint.feb file into PreView 1.3.1.1332. If I accept the errors, it skips each section and
gives each of the following:

'The element “aggressiveness” (line 15) is unknown. Do you wish to continue? Selecting Yes will skip this element as well as all its
sub-elements.'

'The element “mat_axis” (line 82) is unknown.'

'The element “mat_axis” (line 97) is unknown.'

'The element “density” (line 100) is unknown.'

'The element “density” (line 111) is unknown.'

'The element “density” (line 122) is unknown.'

'The element “density” (line 133) is unknown.'

'The element “density” (line 144) is unknown.'

'The element “plotfile” (line 231878) is unknown.'


If I do not accept the error, then I get this message:

'Failed importing FEBio file. FATAL ERROR: unrecognized tag
"aggressiveness" (line 15).'

It appears that PreView 1.3.1 may not recognize all the keywords in the tf_joint.feb file. While we can ask PreView developers to implement these keywords for FeBio file import in the software, a cumbersome workaround maybe:

- Make a note of all errors.
- Build and/or change your model as you wish in PreView.
- Export your model
- Edit your model in a text editor to incorporate skipped definitions (as described by the errors)

Notes:

1. aggressiveness relates to time stepping approach in FeBio. If not set, the convergence may not be possible or really slow.

2. mat_axis refers to material definition of menisci as orthotropic material.

3. density refers to material definition of all model structures; needs to be specified for implicit dynamic analysis used in Open Knee.

4. plotfile section relates to additional output requests to be written; needs to be specified, if contact pressure is desired as an output.

Ok, that sounds good and no rush editing PreView. I will use this workaround to build my model and thank you for explaining those keywords...its helpful to understand a bit more about the code. I appreciate your help!