implementing a module to export a mesh to specific format is not that difficult. The transfer seems quite complicated, but it's just for testing reasons. If you used mm units in FreeCAD and meter units in fenics you have to rescale the mesh by using x = ordinates() x *= 0.001.Replace the mesh generation command in the demo file by mesh = Mesh('./boxmesh.xml').Use dolfin-convert.py to transform the.Use ("./boxmesh.unv") to export the mesh from FreeCAD into an.Perform FEM Analysis and look at the results.Create FEM Analysis in FC and use gmsh meshing with 3D first order elements (higher order elements are not recognized by dolfin-convert).Plot(u_magnitude, 'Displacement magnitude')įile('elasticity/von_mises.pvd') << von_Misesįile('elasticity/magnitude.pvd') << u_magnitudeįirst of all, I will describe the procedure to export the mesh from FreeCAD into fenics: Plot(von_Mises, title='Stress intensity') S = sigma(u) - (1./3)*tr(sigma(u))*Identity(d) # deviatoric stress Plot(u, title='Displacement', mode='displacement') L = dot(f, v)*dx + dot(T, v)*ds(0) # self load + load on face Return lambda_*nabla_div(u)*Identity(d) + 2*mu*epsilon(u)ĭ = u.geometric_dimension() # space dimension Return 0.5*(nabla_grad(u) + nabla_grad(u).T) V = FunctionSpace(mesh, element, constrained_domain=constrained_domain)īc = DirichletBC(V, Constant((0, 0, 0)), clamped_boundary) Import Įlement = _order(V.ufl_element())Ĭonstrained_domain = V.dofmap().constrained_domain Meshcoords *= 0.001 # mesh read in mm but needed in m Mesh = Mesh(os.getcwd() + "/boxmesh2.xml") #mesh = BoxMesh(Point(0, 0, 0), Point(Len, W, H), 30/scalefactor, 15/scalefactor, 15/scalefactor) Its left end and deformed under its own weight.
The model is used to simulate an elastic beam clamped at Hash: fcd0465d8f891292dc03c95946b7ca8d51348857įc_fenics_demo_gmsh.zip FreeCAD example and Fenics Python script for using the same gmsh mesh via dolfin-convert.py (477.03 KiB) Downloaded 49 timesįEniCS tutorial demo program: Linear elastic problem. PS: I would not be able to focus on the dolfin-convert problem if I would not have your files (The drawback is the introduced artifical stiffness for a coarse mesh.)Īs you can see in the files (timestamp) I also played around a bit with the dolfin-convert.py script.īut it is obviously not sufficient to change the recognizable cell types. So you have to use only 3D and first order elements during gmsh-meshing in FC. msh file, and the 3D elements are only tetrahedrons of type 4 which are known The main problem with dolfin-convert was, that it did not recognize the higher order elements.
#Gmsh define dirichletbc fenics zip
Yesterday in the evening I was too tired, to zip all of the files together
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