# \#juafem

**URL:** https://discourse.julialang.org/tag/juafem/428.md

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## [How to efficiently differentiate backslash operator for sparse matrix?](https://discourse.julialang.org/t/how-to-efficiently-differentiate-backslash-operator-for-sparse-matrix/43778)

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**Author:** [@Liang\_Chen](https://discourse.julialang.org/u/Liang_Chen)\
**Replies:** 23\
**Last updated:** [May 1, 2023, 4:21pm UTC](https://discourse.julialang.org/t/how-to-efficiently-differentiate-backslash-operator-for-sparse-matrix/43778 "2023-05-01T16:21:24Z")

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My problem is to calculate the gradient, dL(u)/dp, where L() is a loss function which takes a vector u as the input and outputs a scalar value. The vector p are parameters that defines a large sparse matrix K, such that K…

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## [Solve strain for given stress in von Mises plasticity](https://discourse.julialang.org/t/solve-strain-for-given-stress-in-von-mises-plasticity/79501)

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**Author:** [@FrootLoops](https://discourse.julialang.org/u/FrootLoops)\
**Replies:** 0\
**Last updated:** [April 14, 2022, 5:23pm UTC](https://discourse.julialang.org/t/solve-strain-for-given-stress-in-von-mises-plasticity/79501 "2022-04-14T17:23:46Z")

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Hi, I am trying to caculate for a given stress the corresponding strain in the Von Mises plasticity example. I know that this results in a non-linear equation. Not notice I have the following equations: σᵗ = C ⊡ (ϵ - ϵ…

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## [Boundary conditions](https://discourse.julialang.org/t/boundary-conditions/54609)

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**Author:** [@Rony](https://discourse.julialang.org/u/Rony)\
**Replies:** 0\
**Last updated:** [February 4, 2021, 10:39am UTC](https://discourse.julialang.org/t/boundary-conditions/54609 "2021-02-04T10:39:41Z")

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I want to select particular nodes in my 2D mesh to apply boundary conditions and traction. I saw the examples where the entire left face have been selected. My mesh looks like this. I want to apply constraint in node 1 …

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## [How can I load a polygonal 2D mesh (VTK format) into JuAFEM?](https://discourse.julialang.org/t/how-can-i-load-a-polygonal-2d-mesh-vtk-format-into-juafem/53831)

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**Author:** [@gedankenexperiment](https://discourse.julialang.org/u/gedankenexperiment)\
**Replies:** 1\
**Last updated:** [January 23, 2021, 10:39pm UTC](https://discourse.julialang.org/t/how-can-i-load-a-polygonal-2d-mesh-vtk-format-into-juafem/53831 "2021-01-23T22:39:11Z")

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Hi, I want to solve a reaction-diffusion equation on a 2D polygonal mesh, where each cell has a different parameter value for the reaction-diffusion equation. I have the mesh in the VTK format. Now I wonder whether I sho…

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## [Assembly prescribed Stress using JuAFEM](https://discourse.julialang.org/t/assembly-prescribed-stress-using-juafem/52178)

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**Author:** [@FrootLoops](https://discourse.julialang.org/u/FrootLoops)\
**Replies:** 1\
**Last updated:** [December 21, 2020, 3:20pm UTC](https://discourse.julialang.org/t/assembly-prescribed-stress-using-juafem/52178 "2020-12-21T15:20:02Z")

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Checking the example incompressible\_elasticity, it is solving the equation Ku = f based on the following assemble code: function doassemble(cellvalues\_u::CellVectorValues{dim}, cellvalues\_p::CellScalarValues{dim}, …

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## [Meshfree methods](https://discourse.julialang.org/t/meshfree-methods/51247)

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**Author:** [@FrootLoops](https://discourse.julialang.org/u/FrootLoops)\
**Replies:** 4\
**Last updated:** [December 6, 2020, 7:55pm UTC](https://discourse.julialang.org/t/meshfree-methods/51247 "2020-12-06T19:55:27Z")

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Hi, are there any known packages or modifications for meshfree methods like IGA Galerkin? I cannot find much in the internet. Maybe someone already modified JuAFEM for these kind of applications?

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## [\_generate\_2d\_nodes! in JuAFEM](https://discourse.julialang.org/t/generate-2d-nodes-in-juafem/49990)

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**Author:** [@Hrishikesh\_Das](https://discourse.julialang.org/u/Hrishikesh_Das)\
**Replies:** 0\
**Last updated:** [November 11, 2020, 4:05pm UTC](https://discourse.julialang.org/t/generate-2d-nodes-in-juafem/49990 "2020-11-11T16:05:49Z")

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I am trying to use the function \_generate\_2d\_nodes! which is available in JuAFEM. But it shows an error. Below is my code using Tensors, JuAFEM M =\_generate\_2d\_nodes!(44, 21, 21, Vec{2}((0.0,4.5)), Vec{2}((0.5,4.5)), …

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## [How to add different meshes in JuAFEM?](https://discourse.julialang.org/t/how-to-add-different-meshes-in-juafem/49769)

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**Author:** [@Hrishikesh\_Das](https://discourse.julialang.org/u/Hrishikesh_Das)\
**Replies:** 7\
**Last updated:** [November 9, 2020, 2:18pm UTC](https://discourse.julialang.org/t/how-to-add-different-meshes-in-juafem/49769 "2020-11-09T14:18:34Z")

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I am using the package JuAFEM. I want to join three different meshes and make it into one. Below is the picture attached. Plz help.

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## [How to properly get coordinates with a ::Grid structure](https://discourse.julialang.org/t/how-to-properly-get-coordinates-with-a-grid-structure/45392)

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**Author:** [@jmura](https://discourse.julialang.org/u/jmura)\
**Replies:** 1\
**Last updated:** [August 24, 2020, 4:35pm UTC](https://discourse.julialang.org/t/how-to-properly-get-coordinates-with-a-grid-structure/45392 "2020-08-24T16:35:13Z")

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Dear all, I’m a newbie at Julia. Probably I’m doing something wrong and/or inefficiently: I was trying to replicate one of the examples to generate my own linear elasticity solver. Starting with a very simple example (f…

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## [JuAFEM mesh issue](https://discourse.julialang.org/t/juafem-mesh-issue/41467)

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**Author:** [@bocc](https://discourse.julialang.org/u/bocc)\
**Replies:** 19\
**Last updated:** [July 18, 2020, 1:07pm UTC](https://discourse.julialang.org/t/juafem-mesh-issue/41467 "2020-07-18T13:07:36Z")

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Hello, sorry in advance for posting this here, as this is most likely not a JuAFEM issue, but a problem with an external mesh. Also apologies for not being able to create a copy-pastable MWE. Any insight is appreciated …

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## [Issue with the incompressible elasticity example of JuAFEM package](https://discourse.julialang.org/t/issue-with-the-incompressible-elasticity-example-of-juafem-package/34814)

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**Author:** [@Leooop](https://discourse.julialang.org/u/Leooop)\
**Replies:** 3\
**Last updated:** [February 20, 2020, 12:33pm UTC](https://discourse.julialang.org/t/issue-with-the-incompressible-elasticity-example-of-juafem-package/34814 "2020-02-20T12:33:08Z")

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Hi, I plan to use the JuAFEM package as a basis for my phd work dealing with brittle damage modeling. First of all, I would like to thank the authors(@kristoffer.carlsson et @fredrikekre) for this beautifully written p…