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# Ravi Kumar

### University of Illinois

Last seen: 8 dagar ago Active since 2016

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Why do I get zero Thermal Stress? Am I using the PDE Toolbox incorrectly?
Got it. You don't have CTE specified along with the material properties. Refer to structuralProperties() call in the bi-metal ex...

ungefär 2 månader ago | 0

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Using XY Data from this example? Help please
You can use interpolateStress to find values of stress at a given query coordinates (xq,yq,zq),. Regards, Ravi

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Can someone help me with this Matlab code on 2D heat equation
Your T_initial is declared as a scalar, you are getting the error when you try to index into it beyond its size. Make that zeros...

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Pressure units for a 1D edge on a structural model?
When you are solving a 2-D structural probelm (either plane stress or plane strain approximation), unit thickness is implicit. C...

Improve efficiency of AssembleFEMatrices?
If you are using R2020b or newer version of MATLAB, you should be able to specify required matrices as input: https://www.mathw...

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How to give initial guess and initial condition for a nonlinear - time dependent PDE problem (transient non-linear heat equation) in pde tool box?
For nonlinear elliptic problem, inputs in setInitialCcnditions is the initial guess for the nonlinear solver. For time-dependent...

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How to get AssembleFEMatrices for a nonlinear and Time dependent PDE problem in PDEtool box
Solution matrix must of of the size NumPDEs x NumNodes. In your case, you are providing several solutions at all the time-steps ...

Display generated mesh/ call out adjacent nodes in 3D domain
Check findNodes function. You should be able to specify region as box in which you need node IDs. Regards, Ravi

How to mesh mutliple objects?
This example might work for you!

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Unable to resolve the name results.NodalSolution.
You have a typo. It should be u=result.NodalSolution; not u=results.NodalSolution; Regards, Ravi

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PDE: modal analysis two bodies - possible?
Hi Rober, Your mass density seems to be off. If you are using SI units, as it appears from Young's moduls, mass density must b...

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PDE toolbox, specifying coefficients, error telling me "Function specifying a coefficient must accept two input arguments and return one output argument."
The function "fcoeffunction", does not have definitions of e, L, C, mu, r, o, etc. in its scope. Move the definitions in the beg...

Issue with STL geometry and pde toolbox
Check the dimensions of the expoerted geometry. Some tools export by default in mm, you mght be seeing many more frequenceis if ...

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Thermal contact resistance in PDE toolbox
Hi Luca, Interface conditions like thermal contact resistance are not yet supported in PDE Toolbox. Regards, Ravi

Set non-constant boundary condition proportional to solution at that point and time
Hi Ollie, The function you have written does exactly what you describe. What is the issue you are encountering? Regards, Ra...

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Transient thermal model (PDE Toolbox) failing to solve due to time dependent heat flux and ambient temperature. "Unable to meet integration tolerance."
Hi Kevin, Make sure your geometry from STL is in SI units too as you have properties specified in SI units. I don't see anythi...

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Transient heat flux boundary condition in PDE toolbox
Based on what you describe, it appears you are assigning heat flux on an interior edge. These are not boundaries of the domain s...

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PDE Toolbox FEA Units
Hello Colton, You are right, PDE Toolbox does not have any units. Two things you can check again: You save E as 10300000 psi i...

PDE TOOLBOOX heat transfer error
You are overwriting modelc immediately after creating the thermal model. Remove the second line: modelc = createpde

ungefär ett år ago | 0

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Can I use the figure’Blade.stl’ file provided in PDE Toolbox for publication (copyright)?

ungefär ett år ago | 0

Interpolating at centroid of a tetrahedral mesh
You can use interpolateSolution if you are using equation based interfaces to setup the problem. If you are solving a structural...

ungefär ett år ago | 0

Radiation heat transfer using PDE toolbox
Hi Ruben, Thanks for the code, it helped. All the BCs inside RadandConv == 1 block are applied on the edges that are interior ...

ungefär ett år ago | 0

Finite Element Analysis in Matlab with user-defined elements?
You can define user defined functions of space, time, and solution using PDE Toolbox generic workflow, check out the following l...

ungefär ett år ago | 0

Boundary Condition for 3-D Poisson's Equation using PDE Toolbox
You need BC for all three equations. You might want to try u as [0;0;0] or other appropriate vector of 3 rows, where each row co...

ungefär ett år ago | 1

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How can I extend the functionality of PDE tool box
Hi Jammi, You might want to explore the generic equation based workflow that solves the equations that can be cast into the sup...

ungefär ett år ago | 1

I can't use "structuralProperties" in PDE toolbox
Change the line: thePde = createpde(); to thePde = createpde('structural'); By default, createpde returns a model that has...

ungefär ett år ago | 0

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Plotting points from a 3D model onto a 2D graph
You can interpolate the temperatures at (x,y) coorinates over time and plot them. Refer to interpolateTemperatue function. Rega...

ungefär ett år ago | 0

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Interpolation of the results from the PDE toolbox and the spatial differentiation of the solution
You can do this using interpolateSolution and evaluateGradients. Regards, Ravi

ungefär ett år ago | 1

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