{"id":451947,"date":"2026-02-04T03:04:16","date_gmt":"2026-02-04T03:04:16","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/ale-axisymmetric-simulation-in-ls-dyna-with-volume-fraction-geometry\/"},"modified":"2026-02-04T03:04:16","modified_gmt":"2026-02-04T03:04:16","slug":"ale-axisymmetric-simulation-in-ls-dyna-with-volume-fraction-geometry","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/ale-axisymmetric-simulation-in-ls-dyna-with-volume-fraction-geometry\/","title":{"rendered":"ALE axisymmetric simulation in LS-DYNA with volume fraction geometry?"},"content":{"rendered":"

<p>When I am using the workbench, there is no option of ALE bodies under model. So i thought that using the LS Prepost might work. So I have imported the mesh from the workbench together with the keyword file. Then I made ALE2D and so on.<br>The issue comes from material groups and used Volume fraction geometry to “patch” the bodies in the background domain. So firstly it needs some VOID parts, I have created them but it does not seem that Volume fraction geometry lets me input them. But for some reason presense of those eliminate the “cannot find void body” error. Then I am keep getting<br><br> *** Error 21153 (STR+1153)<br>     Flag BAMMG = 2 specified in card *INITIAL_VOLUME_FRACTION_GEOMETRY<br>     is out of range. It is an ALE AMMG ID and its value should<br>     be greater than 1 and less than 1.<br><br>I have tried switching the ID of the AMMG around, from 1 to 4, but it would only show up as 2, 22, or something. <br>Does anyone know what is going on? ID being greater than 1 and less than 1 means it cannot be 1, but it is not 1.<br><br>(The following pic is me putting BAMMG on 1, same error message) <br><br><br>I am just confused how would you run a axisymmetric ALE simulation in ls dyna in general, <br>I was thinking <br>1) make mesh in workbench since its easier and do all the setup that is avaliable <br>2) import into LS dyna and they all come as shell bodies due to unavaliability of ALE, change them all to ALE2D<br>3) use volume fraction geometry to patch them on the ALE background that we made before in workbench (already ALE2d)<br><br>Idk why this doesnt work. <br>The issue of me not making mesh in ls dyna is because the shape I am tyring to run is irregular, and very hard to draw in ls dyna. <br>Do i need to do something with the axis of symmetry? Doesn’t it already transfer write together with the workbench written k file? What about boundary? <\/p><\/p>\n","protected":false},"template":"","class_list":["post-451947","topic","type-topic","status-publish","hentry","topic-tag-2d-axisymmetric","topic-tag-ale","topic-tag-volume-fraction"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t