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Showing posts from December, 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

CMS Superelement Harmonic Analysis

Fig 1: Project Schematic With the release of Mechanical 19.2, substructuring is now available for Modal & Rigid Dynamics without scripting. That just made my  earlier post on CMS outdated! Note that there is still a key limitation where Generation and Expansion Pass must be performed on your local machine. To get ahead of the game a bit, here is a way to do Harmonic Analysis extending on previous work . (Please go through that before this post). Some points of note: The method of merging the CMS and non-CMS models together into System C is the same. All files related to the superelement has to be copied over to the solver file directory as before. Modal analysis need not be performed first as the example here uses  Full Method  instead of Modal Superposition for simplicity.  The script expands the responses the same way as Modal Analysis does so the script will look familiar. Additional Resources: Example: Harmonic Response to Unbalanced Force using CMS ( Link ) Exa

Learning Python for Ansys and Beyond

Figure 1: Colab by Google Ansys has  ACT extension where users can do some customization using a popular programming language called Python. The barriers to learning Python is now much lower but I'm still stumped by Object Oriented Programming. Hopefully this post would be useful to those who fit the following demographics: Knows simple programming concepts like loops and functions Understand some Calculus Side Notes on Ansys ACT Before You Begin Ansys uses  IronPython 2.7  which is an implementation in the .NET framework. Unfortunately, as I understand it, some libraries such as NumPy are difficult to install . Colabs Colaboratory Research by Google (Fig 1) is a neat tool. All you need is a free Google account and you can execute Python scripts in the browser. No installation required! It has Jupyter notebook running in the background and allows both Python 2 or Python 3. While NumPy and Matplotlib is already installed by default, you could install other librarie