Questions tagged [gmsh]

A three-dimensional finite element mesh generator with built-in pre- and post-processing facilities

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1answer
45 views

Parametric surface in 3D

I want to create a mesh for a 3D surface with coordinates defined by a parametric function. Is it possible to define this mesh using Gmsh? If it is not possible, what free software do you recommend me?...
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1answer
52 views

Generating structured paraboloid using gmsh

I am trying to get the structured mesh as shown in the figure. I have used the transfinite surface and curve to achieve the same. Though I get the structured mesh but I do not know how to do for body-...
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27 views

OpenFOAM: Using icoFoam after snappyHexMesh

I am trying to run icoFoam through a geometry made by Gmsh. For meshing, I have used snappyHexMesh. For that I had the geometry made with Gmsh by someone else and converted to a *.stl file. The ...
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0answers
39 views

How can I improve the accuracy of the calculation of the magnetic field in Gmsh/GetDP?

I need to calculate the magnetic field along a straight line in proximity of an array of 6 magnets. I used the tutorial files "magnets" included in Gmsh and I slightly modified the file in ...
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2answers
178 views

Meshing surface of a sphere with a subdomain

I am trying to build a triangle mesh of the surface of a sphere which also includes a subdomain defined by a 'polygon'. Here is a successful example (subdomain defined by the red dots): Note that the ...
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Hi I am trying to model a 2D Lug angle using Gmsh 4.6. How can I combine transfinite quad and regular full quad meshes in the following geo file?

I need transfinite mesh a small section of the bolt hole to insert a crack. However, The transfinite mesh and regular full quad mesh seem being incompatible and throwing errors. How can I combine ...
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1answer
80 views

Going From Blender Structure defined by triangles to full 3D mesh (Using GMSH?)

I currently have created a model airplane in Blender by drawing a closed volume with triangular planes. I want to do a FEM calculation on this object, meaning I need a fine 3D tetrahedral mesh of this ...
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1answer
41 views

Does 'Recombine' work for this geometry in Gmsh?

I am struggling to recombine the remaining triangular cells into unstructured quadrangular ones in this geometry using Gmsh. Do I need to add auxiliary lines somewhere or do some geometries just don't ...
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178 views

Adding a boundary surface on a STL model in Gmsh

Background info I want to run brain simulations with models from the PHM repository (not relevant to the problem but suits the narrative) which are shipped in STL format. The meshes of the STL have ...
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1answer
40 views

Convert existing gmsh mesh from first- to second-order elements?

Is there a way to take an existing gmsh .msh file, and convert it to second-order elements? Specifically, I'm trying to go from 8-point hexahedra (hex8) to 20-point hexahedra (hex20). Ideally, I'd ...
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1answer
51 views

Why addCylinder function not respecting the given coordinates?

I tried to generate 3 very simple cylinders, each other connected to it end, however the cylinder get connected to an unexistent point in space as the image shows: It was supposed to each segment be ...
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1answer
402 views

Gmsh for .inp file

How do I get an .inp file from Gmsh? I need to create a simple geometry and mesh it and define the boundary conditions in Gmsh and export it as an ...
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1answer
88 views

Creating a mesh around an 1-D line to form a 2-D object

Given the following code, how can I perform a mesh generation around the line, to make a 2D form in GMSH API? Extrude or Mirror ...
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1answer
118 views

Retaining or mapping sets (physical tags) after remeshing a compounded surface/curve in Gmsh?

For my current work, I need to remesh a given geometry with Gmsh (currently trying all Gmsh versions to achieve this) to continue my Abaqus simulations. As can be seen in the image, the geometry has ...
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0answers
196 views

Heat diffusion simulation in a 3D piston using FENICS

I'm trying to simulate the heat diffusion in a 3D piston. I marked the boundaries on GMSH. I have used a Dirichlet BC of 300 on the top face of piston. But the results look abnormal. There is a ...
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1answer
480 views

Multi-domain 3D Geometries for MATLAB PDE Toolbox

In principle the PDE Toolbox in MATLAB can handle multi-domain 3D geometries as noted here. This feature and the associated function geometryfromMesh were introduced in MATLAB R2018a. The associated ...
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1answer
108 views

Gmsh meshes flat faces incorrectly for cylindrical faces

I have some C++ code that generates meshes from step files and then analyses these meshes for visibility of the faces from different viewing directions. I currently use CGAL but I would like to switch ...
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0answers
120 views

Is it possible to retain sets (physical tags) after remeshing the model in Gmsh?

I am currently working on a remeshing algorithm for Abaqus using Gmsh as part of my Bachelors thesis and I seem to be stuck at some point. I am able to remesh .geo and .msh files using the script ...
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1answer
1k views

Is it possible to remesh with gmsh?

I am currently working on remeshers for my simulations (academic purpose) and I try to find a method to remesh previous meshes using Gmsh. The first mesh (normalMesh.msh) was created using a .geo file ...
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0answers
202 views

Duplicate Surface Meshes in different Gmsh files

My objective is to get a conformal surface mesh between two geometries meshed independently in different files. By example, I can start with a simple cube in one .geo file and mesh this geometry. ...
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2answers
5k views

Creating 3D Mesh from stl files with gmsh

After long hours of searching for an answer I thought it might be better to ask the community. The problem I have is that I need to convert STL files to mesh files. I know that I therefore need to ...
4
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1answer
107 views

Definition of Lagrange nodes in Gmsh

When gmsh uses higher-order tetrahedral elements, there is an underlying Lagrange basis used to specify the map from reference space to the element. I'm trying to load a gmsh mesh of 3rd degree ...
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1answer
265 views

Node re-numbering in 1D mesh GMSH

I'm working with Gmsh to generate 1D meshes of polygon edges. I have noticed that drawing a polygon by "vertices and lines" the program always assigns to the first N nodes of the mesh the coordinates ...
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1answer
1k views

How can I coarsen a mesh in Gmsh when 'Mesh options' include 'Refine by splitting' but nothing about coarsening?

I am new to Gmsh and I am having trouble creating a circle with a coarse mesh. I use Geometry->Elementary entities->Add->Circle to create the geometry ...
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1answer
469 views

Gmsh: Recombine 2D in script file or command line

I have many STL files and I want to reduce their size, so I use Gmsh in this way: gmsh -2 -bin -format vtk -o file.vtk file.stl -0 It reduces the size from 7 MB ...
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0answers
696 views

Gmsh for 3D volume with inclusions [closed]

In an attempt to create three-dimensional volumes with inclusions in Gmsh I stumble upon a problem which was non-existent in the two-dimensional case. I'm using the OpenCASCADE geometry kernel ...
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1answer
843 views

C++ library unstructured mesh writer to VTK format (or similar)

I am working on a 2D unstructured code in C++. I am using gmsh to generate a 2D unstructured mesh and reading it into my program with a library called ...
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1answer
4k views

Creating a proper quad-mesh in GMSH for an “I”-shaped geometry

I'm trying to make a 2-D quad-only mesh of an "I"-shaped cross-section, with elements of size 5. So far I've managed to make it quad only, but some elements are very distorted when they shouldn't be. ...
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1answer
993 views

A difference running Gmsh in command line and in GUI for 3-D mesh generation [closed]

In Gmsh, I have a test.geo file. The question is: if I run gmsh -3 test.geo in the command line, I get the below error. ...
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1answer
150 views

Gmsh exporting wrong mesh DATA [closed]

so hopefully I'll be using gmsh to make meshes out of 2-D cross sections with o thickness. I tried to make a structured mesh with quad elements of a rectangular ...
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0answers
64 views

surface triangulation to boundary representation

Are there any open source tools available which can take a surface triangulation of mesh volumes and convert them to a boundary representation? I am interested in refining multiple region tetrahedral ...
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1answer
5k views

Custom Mesh Sizes in GMSH [closed]

I have a simple question today. I am new to GMSH and I am currently learning how to use the software program. I am using GMSH 3.0.4. What I am looking to do is to set a different mesh size for ...
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2answers
675 views

Combined translational and rotational meshing in gmsh

For a flow simulation I am trying to reproduce a specific screw element design for an intermeshing co-rotating twin-screw extruder. I am using gmsh (v2.16) where the element is made from a 2D surface ...
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1answer
1k views

what is the meaning of mesh smoothing steps in Gmsh?

In Gmsh mesh option list ,there is a smoothing concept, what does this mean and what is the effect of its number to the mesh quality?
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0answers
740 views

Meshing two parts together [closed]

I have two parts, which need to be meshed. One part is located inside another. To simplify the problem, imagine two cubes: one inside another. Geometries are stored in STL files. From CAD point of ...
4
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1answer
2k views

Using Gmsh to create a mesh with zero thickness (quad) interface elements

I acknowledge the following post where a similar question is posed and a very nice answer has been provided: Is there a mesh generator that will generate zero thickness elements for interfaces? ...
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1answer
2k views

Triangular mesh of a 3D surface

I have an irregular grid of points describing this surface (a large subduction fault in South America). The color is depth. Anyway I have 3D coordinates (lon,lat,depth) at irregular intervals. I'm ...
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1answer
3k views

Convert STL file to other formats like .msh (Gmsh) and .inp (Abaqus)

After reading some stuff on STL files, I realized that they do no contain information about a mesh (connectivity for instance) , but they represent the surface geometry of the part to be meshed. ...
2
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1answer
2k views

Gmsh - dividing a plane surface

How to divide a surface to subdomains, which can be recognized in msh file? Avoiding duplicated nodes is necessary. In general I have geo file which contains definition of smaller and bigger region, ...