Volume Mesh
A volume mesh fills the interior of a 3D object with solid elements. Unlike surface meshes that only represent the boundary, volume meshes discretize the entire volume and are essential for finite element analysis (FEA) and computational simulations.
What is a Volume Mesh?
A volume mesh consists of:
| Component | Description |
|---|---|
| Nodes | Points in 3D space |
| Elements | 3D shapes connecting nodes (tetrahedra, hexahedra) |
| Faces | Boundaries between elements or at the surface |
| Edges | Lines connecting nodes |
Element Types
| Element | Shape | Nodes | Use Case |
|---|---|---|---|
| Tetrahedron | 4-sided pyramid | 4 | Complex geometries, automatic meshing |
| Hexahedron | 6-sided box | 8 | Structured grids, higher accuracy |
| Wedge/Prism | Triangular prism | 6 | Boundary layers |
| Pyramid | Square-based pyramid | 5 | Transition between hex and tet |
Tetrahedral meshes are most common for complex organic shapes because they can conform to any geometry.
Creating Volume Meshes
Volume meshes are generated from:
| Source | Description |
|---|---|
| Surface mesh | The surface defines the boundary; interior is filled |
| Mask | Direct conversion from segmented regions |
Mesh generation involves:
- Defining the boundary (from surface mesh or mask)
- Filling the interior with elements
- Optimizing element quality
Mesh Quality
Element quality affects simulation accuracy:
| Metric | Description |
|---|---|
| Aspect ratio | Ratio of longest to shortest edge; closer to 1 is better |
| Skewness | Deviation from ideal shape; lower is better |
| Jacobian | Measure of element distortion; positive values required |
| Element size | Smaller elements = more accuracy but longer computation |
Common Uses
Volume meshes are used for:
| Application | Description |
|---|---|
| Structural analysis (FEA) | Stress, strain, deformation under load |
| Thermal analysis | Heat transfer and temperature distribution |
| Fluid dynamics (CFD) | Flow simulation through or around objects |
| Electromagnetic analysis | Field simulations |
File Formats
| Format | Description |
|---|---|
| VTK/VTU | Visualization Toolkit format |
| MSH | Gmsh mesh format |
| INP | Abaqus input format |
| NASTRAN | Nastran bulk data format |
Volume Mesh vs Surface Mesh
| Volume Mesh | Surface Mesh |
|---|---|
| Contains interior elements | Only boundary faces |
| Required for FEA/CFD | Used for visualization, 3D printing |
| Larger file size | Smaller file size |
| Tetrahedral/hexahedral elements | Triangular faces |
Related Topics
- Surface Mesh – Boundary representation
- Masks – Source for mesh generation