Creation of an input for Random Fields

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Hello

Thanks for your question about random fields. We have a not-yet-published module for random field discretization that works with UQLab… but it is not yet ready for delivery. Too bad !

In any case, your INPUT object should contain your input standard normal variables that are used to generate realizations of your random field (BTW: don’t use a Gaussian random field for Young’s modulus, but a lognormal one!).

Then you should embed the evaluation of the RF realization, followed by the finite element run into a Matlab function that will become your MODEL. This is what is called a wrapper, something like:

function Y = myFiniteElementOutput(X)
% X : one realization of your standard normal vector 
%     (function not vectorized here for simplicity)

% Generate the random field realization
RFvalues = GenerateRandomField(X, Mesh);

% Pass this realization as a FE input file
... % your job!
% Run FE model and retrieve the result
Y = ...
end

and in your UQLab script:

mOpts.mFile = 'myFiniteElementOutput';
mOpts.isVectorized = false;
myModel = uq_createModel(mOpts);

I don’t think the simplified syntax provided by UQLink would help you in this respect, as you have a pre-processing step for generating your random field.
I hope it is clear enough!
Best regards
Bruno

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