To generate the volumetric 3D mesh clic on “Modules/Mesh/3D”. To generate your surfacic 2D mesh simply clic on “Modules/Mesh/2D”. You can change the size of the elements (Element size factor) to get fine or coarse meshes. We recommend to use the “MeshAdapt” algorithm for the 2D generation. Several options are available to optimize your mesh. To generate a 2D mesh and a 3D mesh adapted to simulation, we propose to use GMSH. Deformations are only possible on the nodes of the mesh, a triangle can not bend. There is often not enough points to allow deformations (see the result in the following images). Becareful if you want to use this mesh for simulation, either for the visualisation or the collision model, because the mesh may not be suited. Using FreeCAD you can directly export your mesh using the “.stl” or “.obj” format (sufficient for 3D printing). We mainly remove the sharp angles to ease the 3D print of the mold, and the casting stage of the silicone. Here we will add what we call a “fillet” ( ). Now we can both the surface and the inner cavity. You can change the view of the object (right clic on the model, appearance…). Select both objects and combine them into a single object using the “fusion” tool ( ). and the second one generated by the “mirror” tool.the first one generated by the “revolve” tool.Now we use the “mirror” tool ( ) to get our final shape. The next step is to use the “revolve” tool ( ) to create the solid. When working with cavity, you can either include the cavity in your sketching or create the cavity later and use the boolean operation tool (difference) to remove the matter. See for exemple this video for a detail tuto. Here are the tools to draw your sketch ( ) and to set constraints ( ). When sketching, keep in mind that there are tools to automatically generate symetries. Here we choosed the “complete” workshop, which displays a sample of all the workshops. In FreeCAD you have several workbench (Part, Sketcher…) showing the different corresponding tools. The first step is to sketch your structure. In this section we will give a quick overview of how to design a soft pneumatic actuator using FreeCAD, together with links to more detailed explanations. In the following, we will show an example using FreeCAD for the design and GMSH for the mesh generation. For CGAL, a dedicated plugin is available within the SOFA framework (see a documentation here). Several tools also exist for volume meshing such as GID ( ), CGAL ( ), or Gmsh ( ). Several tools exist for 3D modelisation such as OpenSCAD ( ), FreeCAD ( ), or Blender ( ). The aim of this tutorial is to explain how to design a closed surface description made of triangles, and create a volumetric mesh from it. This volume, referred as volumetric mesh will serve as a domain for FEM computation. blockset with a specific name to add material properties, boundary conditions, loadings.In order to simulate a mechanical object using Finite Element Modeling (FEM), a discrete version of its volume is required. Generate MoFEM-compatible input mesh in *.h5m format using read_med toolĪs mentioned above, the mesh created by Gmsh does not contains attributes that may be needed for some tasks for analysis in MoFEM, e.g.Create a config file to add information (block name, material properties, boundary conditions, loadings) to the defined physical groups (blocksets). ![]() We would need to provide additional information to the defined physical groups (blocksets) and convert the mesh to *.h5m format. The mesh created by Gmsh in the previous step is not immediately compatible in a MoFEM analysis. ![]() then choose the file type Mesh - MED (*.med) and give a file name, e.g. This can be done by go to File -> Export. Then provide the geometry inputs including location (X, Y, Z) and dimensions (DX, DY) as shown in Figure 1 and click Add and then press q on the keyboard to finish.Ī preferred mesh format that will be exported is MED. In order to create a geometry of a square, from the panel on the left, choose Modules -> Geometry -> Elementary entities -> Add -> Rectangle. The data presented in this tutorial can be found at the directory /mofem_install/mofem-cephas/mofem/users_modules/tutorials/msh-1Īmong a number of tutorials on Youtube regarding Gmsh, a tutorial presenting how to create a 2D mesh can be found here. Use read_med to generate a MoFEM-compatible input mesh.Create a seperate config file to add attributes to blocksets (physical group).Create geometry, physical group and mesh in Gmsh.This tutorial shows how to create a simple 2D square mesh in Gmsh with some physical groups and then use the MoFEM tool read_med to generate a MoFEM-compatible input mesh for analysis. use a MoFEM tool called read_med to generate a MoFEM-compatible input mesh.create a seperate config file to add attributes to blocksets.
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