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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

Advice for Enterprising Engineers

This post fits squarely in "other thoughts" category. Some engineers asked for my advice on advancing their careers. To avoid giving bland advice, I hope these strategic framework might help guide their decisions.

Be a Hero

What does it mean to "Be a Hero"? It means you have to achieve something many people in the company will say is significant. It could be improving a tedious process, solving a customer issue that's been a pain in the rear for too long or introduce a tool that solves an unsolvable problem in the past. Let's call these "Hero Problems".

To be a hero, you will have to first develop an understanding of what the company needs. All companies will have their share of problems. Ask around, pay attention when coworkers say phrases like "I wish we could..." or "this is ridiculous, we should...". These offer clues on real Hero Problems.

But why? Why should this be a strategy? This is the "Demand" side of the economic equation. We only profit by intelligently supplying to the demands of the market. Otherwise, we run the risk of spending too much time and resources on chasing something that is unprofitable. We have to manage our time well.

With this in mind, we now turn our attention inwards. What are our strengths? What Hero Problems can we solve in the near term? What skills do we need to develop in order to solve harder Hero Problems? We can then mentally rank what can be accomplished short term and scheme on solving longer term, bigger Hero Problems. It provides the emotional fuel to learn the system, improve your skill set.

By aiming to become a hero, it answer questions like:
Q: "Which Finite Element Analysis (FEA) Software should I learn?"
A: "The FEA software used by the company."

Q: "How do I get resources?"
A: "Pay attention to how resources are distributed in the company & interpersonal skills needed."

Q: "What development classes should I take?"
A: "Those that can help solve Hero Problems."


As an engineer, it is tempting to learn everything interesting and soak up knowledge. I beg to defer. New engineers should instead focus on a narrow field to be productive as soon as possible. Just pick something, any thing that shows promise. Sharpen your skills. Listen carefully to advice, both solicited and not. Consider deeply what is being said. Although not all advice is good, find the gem that might be hiding under your emotional resistance. Invert, always invert.

The reason one should focus on being productive quickly is that it provides proof you can actually do something valuable. Only by showing results, can you attract quality mentors. Good mentors are busy and don't want to waste time on unpromising engineers. Seeking mentors is counterproductive. Do good work and others want to be on the journey with you. Being in a fellowship with cool people is perhaps one of life's greatest pleasures. 


Be humble. Keep doing the good work. There will be a point in time where the value of good work done is so overwhelming that it cannot be ignored. Always recognize others who have helped you. They will appreciate it and will in turn recognize your work. 

Paradoxically, your goals should be internally driven. Instead of shooting for a promotion, aim instead to do work that will be highly valued. Focus intently in the work to find joy in it by pushing yourself. 

Good luck!


  1. Thank you, I learned the most important things is company urgent need to do


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