Newton-Raphson Residuals (2)

As a follow up to the previous post, here's my slightly different take of the Newton-Raphson Residuals.

The help manual shows a nice gradually decreasing stiffness curve (similar to Figure 1). It didn't match what I learned in school or Wikipedia where the algorithm was used to find the root. By rephrasing the question as finding the root for the Newton-Raphson Residual (External - Internal Force), one then gets to Figure 2.

The Octave/Matlab script used to create the above plots can be found here.

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ANSYS User Defined Results

There is an abundant of options in ANSYS classic when one wishes to post process results. ANSYS workbench default pull down menu post processing options are more limited but they can still be accessed via the User Defined Results. One way not commonly used but can come in handy is as follows: Zeroth: Under Analysis Settings, there is "Output Controls" where you can toggle to "Yes" what you would like to save before the solution starts. This is like OUTRES in APDL. Output Controls First: After solving the model, click on Solution in the tree to highlight it. Solution Second: Click on Worksheet in the toolbar. Worksheet Third: In the worksheet, you will see list of results that are saved. Right click on it to create the User Defined Results. Create User Defined Results So here we have it. You could of look up the different expressions in the help document but I find this method of accessing the results convenient. Example: Aspec

Export Stiffness Matrix from Ansys

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ANSYS APDL Syntax Highlighting editor

Notepad++ with APDL User Defined Language The editor of my choice is Notepad++ with the available User Defined Language Files for APDL. You can install it without administrative privileges via the zip file. The best part of it is, it's FREE! After installing Notepad++, go to "Language>Define Your Language..." then "Import" the XML file downloaded from the above link. Remember to restart Notepad++ so that the language changes will take into effect. Opening up any *.inp or *.ans files should automatically switch highlighting to APDL. I made some minor edits. Here's my XML file: LINK . I also heard Sublime Text and Ultraedit has more advance features but they aren't (totally) free.

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