Craig bampton model reduction

Hello all.

I have a pde model with the following characteristics:

PDESystemSize: 2

IsTimeDependent: 1

Geometry: [1×1 AnalyticGeometry]

EquationCoefficients: [1×1 CoefficientAssignmentRecords]

BoundaryConditions: [1×1 BoundaryConditionRecords]

InitialConditions: [1×1 InitialConditionsRecords]

Mesh: [1×1 FEMesh]

SolverOptions: [1×1 pde.PDESolverOptions]

and I need to use craig bampton method to reduce the system. I tried the function reduce

rom = reduce(ModelTwoDomains,'FrequencyRange',[0 1200]);

Due to the error "Incorrect number or types of inputs or outputs for function 'reduce'." I think the problem is that the model is not created as createpde('structural',...) I have also tried the function balred [~,info] = balred(modelTwoDomain) With the following error :

Incorrect number or types of inputs or outputs for function 'balred'.

I am not very sure how to perform this reduction.

Anyone can suggests me something? :S

Thanks again

Answer 1

[Nipun]

Hi Craig,

I understand that you are trying to reduce a PDE model using Balred and Reduce functionality. I assume that you are working with MATLAB R2023.

Note that balred and reduce are not recommended going forward. It is recommended to use reducespec for model order reduction. I assume that you are working with a sparse LTI model and require a balanced method reduction.

R = reducespec(modelTwoDomain, "balanced")
model = getrom(R, order = x)

You may replace 'x' with the required order of the model. Refer to section Input arguments for parameter details. Hope this helps

Regards,

Nipun

[Jorge Garcia Garcia]

will give it a go! thanks!!!