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Showing posts from July, 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

Modal Submodeling

This post was inspired by CAEAI's blog post on modal analysis sub-modeling and an XANSYS question. Their instructions were not explicit and everything was done in Ansys Classic. The goal here is to show modal submodeling in Ansys Workbench. Here's a walk through of an example: Step 1 Solve the coarse model Modal Analysis (System A). Fig 1: Coarse Model Modal Analysis (System A) Step 2 Create a finely meshed submodel Harmonic Response Model (System B). This will be the submodel. Fig 2: Project Schematic After creating the desired mesh, add a named selection at the cut boundaries called  cut_face . Add the following command snippet in the Setup branch. !! Creates cut boundary NODE file ! WB will complain but boundarynodes.node file should be created /prep7 cmsel , s, cut_face nwrite , boundarynodes, node finish /exit The above step writes out a file listing the nodes and their coordinates which will be used for interpolation. After solving for the mode

Ansys Student in the Cloud

Cloud Computing * ? Cloud computing is all the rage now for good reason. It is tempting to own a low cost computer and remote-desktop to a supercomputer. One could, in theory, run Ansys on Chromebook with internet connection by connecting to a Cloud Computing Providers  Virtual Machine. I took a quick look and have the following to report. Setting Up Windows Virtual Machine (VM) : Quick Start Google Compute: YouTube  Micosoft Azure: YouTube1 & YouTube2 Patience is key. After starting up the Virtual Machine for the first time, one has to wait a bit (15 minutes?) before the virtual machine really starts for one to remote login. I fiddled around with the "source IP ranges", setting it to 0.0.0.0 and even my own IP address. It was unclear if that was useful or waiting alone did the trick. Once logged in, one has to override the strict security set by the Internet Explorer to allow download of the free  Ansys Student . Finally, remember to Shut Down from the