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Showing posts from May, 2018

Defining Ansys Superelement SUB File Manually

Photo by  James Owen  on  Unsplash A surprisingly popular blog-post written here is Exporting Stiffness Matrix from Ansys . A sensible follow up question is what can one do with the exported stiffness matrix? In a recent Xansys Forum post, a question was raised on how we can edit the stiffness matrix of a superelement and use it for our model.  An approach presented below is to first create a superelement that has the same number of DOF and nodal location that will serve as a template. An APDL script can then be written to edit the stiffness matrix entries as desired before exporting to a new superelement *.SUB file for use in future models. The self-contained script below demonstrates this.  /prep7 et ,1, 185 mp , ex, 1, 200e3 mp , prxy, 1, 0.33 w = 0.1 ! single element (note nodal locations) n , 1, w, -w, -w n , 2, w, w, -w n , 3, -w, w, -w n , 4, -w, -w, -w n , 5, w, -w, w n , 6, w, w, w n , 7, -w, w, w n , 8, -w, -w, w e , 1, 2, 3, 4, 5, 6, 7, 8 /solu antype , substr     ! analy

Cleaning Up Geometry with SpaceClaim

I sometimes come across a very ugly UGLY message when I try to mesh. The description is especially misleading. Figure 1: Error!  The problem is often fixable in SpaceClaim. Here's something to try: 1. Select everything (Ctrl-A), Right-Mouse-Button then Detach All . 2. Under the Repair tab, click on Stitch and click the green check mark to complete all. Hopefully the first step would solve all problems. You could verify this using the Check Geometry feature. It's not full proof but worth a shot. Figure 2: Check Geometry This would highlight any outstanding problem areas. Other repair tools such as repairing  gaps and missing faces usually does the job. Otherwise, it may be necessary to get more fancy by removing the difficult surface by cutting it (Ctrl-X), then replacing it with blending or  fill .  A really neat trick with fill is Patch Fill. First click on Fill without selecting any geometry. Under the options, the default is Extend Fill . If any geo