ivar_kjelberg

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14 years, 224 days
My current post is "Senior Expert" with 30+ years of experience in mechatronics developments in the frame of complex, multidisciplinary, high tech "systems engineering" activities. Previous posts were "Senior Project Manager, Section Head, Project Manager, Quality Engineer, R&D Engineer. I work in a retained profit company, a "High Tech", R&D Institution, closely linked to the EPFL (Ecole Polytechnique Federale de Lausanne), we are located in Neuchatel Switzerland. We use advanced tools such as Maple, MapleSim and COMSOL Multiphyiscs for our developments and for our Ph.D. training activities.

MaplePrimes Activity


These are answers submitted by ivar_kjelberg

Hi Ian

I'm an entousiast of COMSOL and Multiphysics simualtions in general, I use extensively Maple and in particular MapleSim to perform point checks and verifications of my FEM models. For this the analytical approach of Maple is great, and the clean simple "block" approach of Modelica or Maple's version MapleSim (close to Simulink), makes it very easy and quick to build up simple, and more complex models.

For me COMSOL and MapleSim are very different, COMSOL is a FEM tools taylored to do numerical PDE solving (the first and only one I know about with this large and clean multiphysics approach), while MapleSim is a general analytical mathematical PDE tool built upon the analytical mathematical Solver Maple, and following the methodology of Modelica. For me they are complmentary but in no way one replaces the other. And for most engineering simulations both are required to do a correct job (at least for complex studies going outside of traditions simple schoolbook studies).

I must admint that we also use Matlab and Simulink, but this is really when we talk about numerical simulation and implementation of control laws for our engineering models, based often on COMSOL studies, verified by MapleSim.

But if your are more interested in the mathematics, then probably Maple and MapleSim will have a greater impact, as they are a more general mathematical tool than COMSOL. And if you say "you do not need the geometry" then I interprete this are a greater interest in the mathematics than the engineering (I may be wrong).

Hope this helps on the way

Good luck

Ivar

Hello

To give a partial answer: MapleSim2.0, and Maple 13.01 up to date, on MS VISTA SP1 up to date, on Dell latitude laptop D630.

For the function I was trying to use the Signal Block - Sources - Real - Real Expression block and pasting in my function from Maple (intead of the "sin(time)" default value), but as my Maple code was rather large 1-2 pages it's impossible for me to edit it thereafter, it's slightly easier in the "parameter" tab but still, seem to have some translation problems.

My workaround was to enter a simpler expression and then build a sub-block with integrals of my simpler functions to finsih the work in MapleSim.

This works out quite well, but then I have some trouble with the modulo and/or GE, GT, LE, LT functions depending on solver settigns. I have got there too a workaround for the moment by adding some 1e-7 here and there. (This has been reported to support and they are looking into the issue, seems to be a typical numerical rundoff effect, model validation remains tricky with binary number representation).

For the time being I'm happy again :)

Thanks anyhow

Ivar

Hi,

tanks for the trick, I'll try, didnt think if using same In as Out vaiable, as you need to have both, expected them to have to be different.

Ivar

yes, but its a piecewise function continuously derivable.

When I tried to past in the Maple code, finally everything dissapeared, it's very difficult to edit a big block of text in that windw, even in the parameter window, also the translation process (each time you close the block/window) has some funny behaviour, I suspect that I went over a buffer size for the input text

Any other suggestions, I was thinking of revriting everything as a ODE, and try to have the "dynamic solver to solve it, but there are 4-6 different pieces to get matched. 

Why isn't there an "external function" call for Maple code in MapleSim?

Thanks for the support

Ivar

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