Specification on some GUI commands

  1. From the documentation: assigns elements from multiple separate parts to one common part without changing the mesh
  2. The individual parts are still in the tree in the Geometry tab, you can show and mesh them.
  3. Use the selection modes to make sure that you will select only the desired geometrical entity type.
  4. This is the concept used in Abaqus. It propagates the selection using a specified angle (so only the edges/faces within that angle from the selected one will be added to the selection). From Abaqus documentation (should apply also here):

The angle must be greater than the angle through which adjacent edges or faces must rotate to create the geometry as if it was being formed by bending a straight wire or folding a series of faces. Abaqus/CAE starts from the selected geometry and selects all adjacent geometry until the angle you entered is met or exceeded.

For example, to select the edges of a regular hexagon, enter an angle greater than 60° (since each adjacent edge must be rotated 60° to form the shape from a straight wire), and select one of the edges. Abaqus/CAE then selects every adjacent edge since none of the angles is equal to or exceeds the angle that you entered.

  1. This is explained in the CalculiX manual since it’s a solver feature. It forces the nodes of the slave surface to lie exactly on the master surface so it only makes a correction of the node locations if there are some initial gaps/penetrations.
  2. I’m not sure when part names can become red, probably after some breaking changes in the tree. More often you will see a yellow warning sign indicating issues with imported geometry.
  3. Probably they weren’t read correctly and you should check their contents.
  4. This might be a good idea considering the number of people making this mistake. There’s even a dedicated forum thread for that: Don't apply concentrated force load to surfaces
  5. Yes, moments are per node and mostly applied to reference points. Applying them to solids wouldn’t make sense due to the lack of rotational DOFs. So total moment feature wouldn’t be very useful (moments applied directly to shell edges aren’t so common). Maybe the Surface traction load could be renamed to Total force or something. Your suggestion is a bit too long.
  6. The fixed constraint makes sense when you are sure that you want to quickly fix all DOFs and keep them fixed. Otherwise, you should use the Displacement/Rotation BC. Other FEA software also uses this approach. In Abaqus, you have predefined fixed (ENCASTRE) and symmetry constraints that can’t be changed and general Displacement BC operating on individual DOFs.
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