Create the Finite Element Model

Create a finite element model to represent the geometry during the simulation.

A finite element model representation is an alternative representation of 1D, 2D, or 3D geometries. You can control both the size and type of the elements in the mesh when creating the representation. If required, you can modify these specifications to create new meshes to replace the existing one or to create multiple meshes for use with the simulation.

In Additive Manufacturing Scenario Creation the following mesh types are generated automatically for parts that have associated slicing and scan path data:

  • Tetrahedron mesh - printed parts
  • Sweep 3D mesh - build tray

In this example, we will replace the tetrahedron mesh with a hexahedron mesh for the printed part and support to get more accurate results.

This task shows you how to:

Create the Finite Element Model Representation and Mesh the Build Plate

You can define a finite element model (FEM) representation of your assembly that contains the finite element mesh and associated properties. The assembly to run an additive manufacturing simulation contains the bridge structure (T-shaped printed part and supports) and the build plate.

  1. From the Setup section of the Assistant, click Finite Element Model .
  2. Name the finite element model FEM_AM.
  3. Accept the default values, and click OK.
    The FEM representation of your model appears in the model category of the tree.
  4. From the tree, right-click FEM_AM > Nodes and Elements > TetrahedronMesh.1, and click Delete.

    Tip: Press F3 to display the tree if it is not visible.

    The automatically generated tetrahedron mesh is deleted. In the next steps, we will replace it by using the sweep mesh technique to add a hexahedron mesh.
  5. From the tree, double-click FEM_AM > Nodes and Elements > Sweep 3D Mesh.1.
    The assembly opens in Mesh Creation.
  6. Name the sweep 3D mesh Sweep_3D_buildtray.
  7. Enter a mesh size of 10 mm, and set the number of layers to 10.
  8. Click Mesh, and then click OK.

Mesh the Printed Part and Supports

You can use a partition hexahedron mesh to create a highly structured hex-dominant mesh in a solid part, which is partitioned into multiple volumes. A partition hexahedron mesh contains a mixture of first-order hex-dominant elements and first-order (linear) tetrahedron elements. Often, this combination provides the most efficient way to achieve accurate simulation results.

In this example, the bridge structure has two volumes (a T-shaped print part and its supports) and requires a smooth mesh between the volumes throughout the structure. Using a hexahedron mesh for both volumes ensures a smooth mesh.

  1. From the Mesh section of the action bar, click Partition Hex Mesh .
  2. Name the partition hex mesh Hex_Mesh_Bridge_structure.
  3. From the 3D area, select the bridge structure as the Support.
  4. For Non-hex volumes, select Linear tet.
  5. Enter a mesh size of 0.5 mm.
  6. Click Mesh, and then click OK.
  7. If the mesh is not visible, right-click FEM_AM in the tree, and click Hide/Show.

    Tip: You can use the mouse to zoom the model in and out. To zoom the model, press and hold the middle mouse button; while holding the middle button, click and release either the left or right mouse button, and drag the mouse. To pan the model, press the middle mouse button while dragging the pointer.