FEM: Strato limite di mesh FEM
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| Posizione nel menu |
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| Mesh → FEM Mesh boundary layer |
| Ambiente |
| FEM |
| Avvio veloce |
| Nessuno |
| Introdotto nella versione |
| - |
| Vedere anche |
| Tutorial FEM |
Descrizione
The FEM MeshBoundaryLayer command enables the user to set a localized set of meshing parameters by selecting a set of elements (Vertex, Edge, Face) and applying the parameters to it.
It is especially useful for refining meshes close to edges or surfaces in flow simulations. For example, it can be used to refine the mesh in the vicinity of an air foil or obstacle in a flow.
The boundary layer has the advantage of creating highly defined, anisotropic meshes. As the name implies it supports accurate calculations near boundaries, e.g. a wall where friction occurs, generating a velocity gradient.
Utilizzo
- To enable the command a
Mesh From Shape by Gmsh must be provided first.
- Select the Mesh object in the Tree View.
- There are several ways to invoke the command:
- Press the
Mesh Boundary Layer button.
- Select the Mesh →
Mesh Boundary Layer option from the menu.
- Press the
- Edit the start element size, the growth rate and the number of growth layers.
- Press the Add button. Select a vertex, edge, face. introduced in 1.1: To remove objects from the selection, press the Remove button.
- Click the OK button.
- Close the task.
- Result: You now should see a new
FEMMeshBoundaryLayerobject under theFEMMeshGMSHobject (see example #3 below) in your active analysis container.
- Result: You now should see a new
- Double-click on the
FEMMeshGMSHparent object in your Model Tree and press Apply to force a mesh recalculation. - Close the task.
After the mesh has been created you can change its properties using the Property View. After you changed a property, you must reopen the Gmsh dialog again and click the Apply button. (You can leave the dialog open while changing properties.)
You can create as many different mesh boundary layers as needed.
Visual examples
Example 1: The initial coarse FEMMeshGMSH on a 2D case
Example 2: After applying a Mesh boundary layer
Example 3: A simple example of the resulting Model Tree
- Materials: Solid Material, Fluid Material, Non-Linear Mechanical Material, Reinforced Material (Concrete); Material Editor
- Element Geometry: Beam Cross Section, Beam Rotation, Shell Plate Thickness, Fluid Section for 1D Flow
- Electromagnetic Boundary Conditions: Electrostatic Potential Boundary Condition, Current Density Boundary Condition, Magnetization Boundary Condition, Electric Charge Density
- Fluid Boundary Conditions: Initial Flow Velocity Condition, Initial Pressure Condition, Flow Velocity Boundary Condition
- Geometrical Analysis Features: Plane Multi-Point Constraint, Section Print Feature, Local Coordinate System
- Mechanical Boundary Conditions and Loads: Fixed Boundary Condition, Rigid Body Constraint, Displacement Boundary Condition, Contact Constraint, Tie Constraint, Spring Boundary Condition, Force Load, Pressure Load, Centrifugal Load, Gravity Load
- Thermal Boundary Conditions and Loads: Initial Temperature, Heat Flux Load, Temperature Boundary Condition, Body Heat Source
- Overwrite Constants: Constant Vacuum Permittivity
- Mesh: Mesh From Shape by Netgen, Mesh From Shape by Gmsh, Mesh Boundary Layer, Mesh Refinement, Mesh Group, Erase Elements, FEM Mesh to Mesh
- Solve: Solver CalculiX, Solver Elmer, Solver Mystran, Solver Z88; Mechanical Equations: Elasticity Equation, Deformation Equation; Electromagnetic Equations: Electrostatic Equation, Electricforce Equation, Magnetodynamic Equation, Magnetodynamic 2D Equation, Static Current Equation; Flow Equation, Flux Equation, Heat Equation, Solver Job Control, Run Solver
- Results: Purge Results, Show Result, Apply Changes to Pipeline, Post Pipeline From Result, Pipeline Branch, Warp Filter, Scalar Clip Filter, Function Cut Filter, Region Clip Filter, Contours Filter, Glyph Filter, Line Clip Filter, Stress Linearization Plot, Data at Point Clip Filter, Calculator Filter; Filter Functions: Plane, Sphere, Cylinder, Box; Data Visualizations: Create Lineplot, Create Histogram, Create Table
- Utilities: Clipping Plane on Face, Remove All Clipping Planes, FEM Examples; Clear FEM Mesh, Display Mesh Info
- Additional: Preferences; FEM Install, FEM Mesh, FEM Solver, FEM CalculiX, FEM Concrete; FEM Element Types
- Getting started
- Installation: Download, Windows, Linux, Mac, Additional components, Docker, AppImage, Ubuntu Snap
- Basics: About FreeCAD, Interface, Mouse navigation, Selection methods, Object name, Preferences, Workbenches, Document structure, Properties, Help FreeCAD, Donate
- Help: Tutorials, Video tutorials
- Workbenches: Std Base, Assembly, BIM, CAM, Draft, FEM, Inspection, Material, Mesh, OpenSCAD, Part, PartDesign, Points, Reverse Engineering, Robot, Sketcher, Spreadsheet, Surface, TechDraw, Test Framework
- Hubs: User hub, Power users hub, Developer hub
