hacking structural analysis. join the crew
DESCRIPTION
First of all, don't be scared, this post has nothing to do with evil crackers who want to take control of computers that manage nuclear weapons, it's rather about work (good hard work) and freedom. Almost everyone like music, but it's less common to be aware of the theory (harmony. notation, counterpoint,...) that lies behind the sounds. This post is about structural analysis that, in some way, is to structures (bridges, tunnels, buildings,...) as counterpoint is to music. For structural engineers, computing is (or must be) just another discipline (like mathematics, physics or geotechnics). Implementation of structural analysis programs as practical applications of computing must not be beyond our reach. Rise of free and open source (FOSS) software allow engineering community to develop its own applications (and regain leadership over their discipline) without having to reinvent the wheel.TRANSCRIPT
Hacking structural analysis. Join the crew.
Luis C. Perez [email protected]
February 16, 2016
1 About (your) heroes
First of all in this post the word hacking hasnothing to do with cyber-terrorism or any otherway the bad guys use computers to achievetheir evil objectives. Here a hacker is some-one that wants to know and refuses the idea ofbeing a simple user.
Having said that, if your heroes are MarkZuckerberg, Steve Jobs, Bill Gates,. . . then thisis probably not a post written for you.
But,. . . if the names of Steve Wozniak, Leon-hardt Euler, Hardy Cross, O. C. Zienkiewicz orKlaus Jurgen Bathe make you feel motivatedthen maybe you can find here some ideas thatwhet your appetite (intellectual appetite).
2 Computers & structures,at a glance
Structural engineering is not only about struc-tural mechanics, there are many other disci-plines that an structural engineer must to knowto do his job. However, it’s structural mechan-ics (the scientific part of our knowledge) whatgives meaning and value to our work as engi-neers.
From Galileo’s Two new sciences until theearly applications of numerical analysis to solvestructural problems in the 50’s of the last cen-tury, structural analysis methods and proce-dures are beign expressed (as in any otherbranch of physics) using mathematics.
With the arrival of computers the analysisprocedures began to be expressed not only in
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mathematical language but also in the form ofprograms written in Fortran or Basic.
In the 80’s, the popularization of personalcomputers and the ability to distribute pro-grams in the form of executable code made pos-sible the creation of a computer industry thatinitiates the computing for the masses era. Inengineering offices hand calculators begun to bereplaced by personal computers1
3 Ok, so where is the prob-lem?
This exciting development has also its pitfalls:
1. Structural engineers become users withvery little control (if any) over the sofwarebehavior. In a short time, practical imple-mentation of the algorithms they study atthe school, becomes beyond their reach.
2. Before the emergence of commercial soft-ware the methods for structural analysiswere ready to use by engineering com-munity as soon as they were published.Consider, for example, the impact thatthe publication of the moment distributionmethod2 took on the project of staticallyindeterminate structures. On the contrary,commercial programs are products (not sci-entific papers) so their creation, documen-tation, distribution and (most of all) ad-vertising are made with commercial crite-ria.
3. As a consequence of the commercial spiritmentioned in the preceding paragraph,many of these programs are designed tomake things faster3, not better, not in anew way.
1To illustrate the scenario: a PC version of ANSYS,is released about 1984, SAP-90 is released in 1989 and amyriad of programs with very limited capabilities grownlike mushrooms at these days.
2It is hard to imagine that professor H. Crossthought getting rich with the publication of his method.
3This way, the analysis becomes as boring as fillingthe forms on a tax preparation program.
4 So. . . what’s it all about?
The idea is quite simple: assuming we suc-ceed in our mission4, this alternate 2016 will bechanged into the correct 2016, allowing struc-tural engineers community to regain leadershinover their discipline. In other words, we mustgo Back to the future to transform how wework with computing to do it in the same waywe do with physics, mathematics, geology,. . .
Like with maths or any other academic sub-jet, there is no need to reinvent the wheel;the foundation libraries (and some whole appli-cations) for finite element analysis, computergraphics, geometry modeling,. . . are out there.
5 Join the crew
Well this is it. In case you’ve become interested,you can take a look to the following links:
• XC home page. XC is the translation intopractice of the ideas exposed in this docu-ment.
• XC on GitHub. This is the site where weshare the code.
If you want to collaborate you can do it inmany ways:
Free software project management: if you arean experienced free software project man-ager it would be great if you help us todevelop this one.
4Let’s make a little joke by paraphrasing Doctor Em-met Lathrop.
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Write documentation: if you can write goodEnglish5 and you have a good knowledgeof FEA maybe you want to help us to writethe documentation.
If you can read Spanish then you can help usto translate into English the comments inmany C++ source files. There are alsosome documents written in Spanish thatwait for translation.
Test code: if you know how a finite elementanalysis program works, you can help us totest the code. By now there are 383 veri-fication tests that need to be documentedand many verification tests that need to bewritten.
Write code: if you can write Python and/orC++ code maybe you can take a look here.
Good advice: maybe you can simply tell uswhat do you think/like/dislike about ourproject.
5At least better than me ;-)
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