Importing quadratic elements into PreView?

[hendraw]

We saw that support for quadratic elements was added into FEBio 1.5.2 and are interested in using them for our model. However, when attempting to import an Abaques .inp file into PreView 1.9.1 that has quadratic elements we get an error saying "Error while reading keyword ELEMENT" and the import fails. Attached is an example file that does this.

Is PreView simply not capable of dealing with quadratics yet or is there an issue with the format of the file we are trying to import?

Thanks, Bill

QuadraticSphere.zip

[maas]

Hi Bill,

Yes, PreView supports quadratic 10-node tetrahedrals, however we have not added support for this element (C3D10) in the abaqus importer. This will be fixed in the upcoming version 1.11. In the mean time, one work-around is to import linear tets (C3D4) and convert the elements to 10-node tets using the conversion tool in PreView. This tool can be found in the Mesh panel. Hope this helps.

Cheers,

Steve

[gregscott]

I am actually having the same issue trying to import a .inp file from abaqus. My mesh consists of Linear Hex (8-node), Quadratic hex (20-node), and Quadratic tet (10-node) elements. I get the following error message when trying to import in both Preview 1.10 (stable release version), and 1.11 (development version).

"Failed importing ABAQUS file
Error while reading keyword ELEMENT (line 118665)"

Upon inspection of the code, this is the first line that a quadratic 20-node element set is introduced.

A screenshot of the error and the line of code it is indicating is linked below.

http://i47.tinypic.com/209pvv9.png

Does this mean that Quadratic (20-node) Hex elements are not supported? or is there some other error going on with my code?

Also, If 20-node hexes are not supported via import from abaqus, i'm assuming i'll have to downconvert them to 8-node linear hexes and later upconvert them back to quadtratics within the program. My question then is: will this upconversion step leave my sides straight, or will it "curve" them as abaqus does when meshing quadratic meshes.

[ran.sopher.perrydigma]

I am now experiencing a similar problem (same error message) trying to import either a linear or quadratic mesh I created in Gmsh to PreView (saved as *.inp as the other formats supported by PreView crash immediately).

[maas]

Hi,

PreView supports both 20-node hexes and 10-node tets in the Abaqus reader. Make sure you are using the latest version of PreView from our website. Also, Abaqus uses different types for different flavors of these elements, so maybe you are using a type that we don't support yet. For 10-node tets, make sure to use the C3D10 type attribute and for 20-node hexes you can use C3D20 or C3D20R. If that doesn't solve the problem, please attach a small example file that allows us to reproduce the error on our end.

Cheers,

Steve

[ran.sopher.perrydigma]

Thank you very much. Could you please address the following?:
1) I am using the commercial version I've been provided in July (1.18.1), and I believe it's the most recent one, isn't it?
Capture.JPGCapture.JPG
2) Attached are two files exported from gmsh (*.inp and *.msh), which PreView does not seem to handle well (*.inp culminates in the above error message, *.msh just crashes)... Could you please try to see why?

https://drive.google.com/folderview?...nc&usp=sharing

Regards,
Ran

[ran.sopher.perrydigma]

I have successfully worked around the problem by converting the Tet4 to Tet10 elements in PreView itself. However, the results are completely different (the deformations are *a lot* larger when using quadratic elements, much larger than I would expect) - is it possibly because I did something wrong?