Deciding what needs to be partitioned

When you enter the Mesh module, Abaqus/CAE color codes regions of the model according to the methods it will use to generate a mesh:

  • Green indicates that a region can be meshed using structured methods.

  • Yellow indicates that a region can be meshed using sweep methods.

  • Orange indicates that a region cannot be meshed using the default element shape assignment (hexahedral) and must be partitioned further. (Alternatively, you can mesh any model by assigning tetrahedral elements to the model and using the free meshing technique.)

Context:

For the tutorial Abaqus/CAE indicates that the hinge with the lubrication hole needs to be partitioned to be meshed using hexahedral-shaped elements. Specifically, areas surrounding the hole in the flange must be partitioned. The partitioned hinges are shown in Figure 1.

Figure 1. The partitioned hinges.

Use the following techniques to help you select faces and vertices during the partitioning process:

  • Use a combination of the view manipulation tools, the display option tools in the View Options toolbar, and the tools in the Views toolbar to resize and reposition the model as necessary. (To display the Views toolbar, select ViewToolbarsViews from the main menu bar.)

  • Toggle off the closest object tool in the Selection toolbar to cycle through the possible selections using the Next and Previous buttons in the prompt area.

  • You will probably find the 3D compass and/or the magnification tool and the rotation tool especially useful.

  • When necessary, click the Iso tool in the Views toolbox to return the model to its original size and position in the viewport.

  • Recall that part instances are classified as dependent by default. All dependent instances of a part must possess identical geometry (including partitions) and meshes. To satisfy this requirement, all partitions must be created in the original part and all mesh attributes must be assigned to the original part. You will need to examine the parts individually to determine what action (if any) needs to be taken to create a mesh using hexahedral elements.

    Note:

    The advantage of dependent part instances is that if you create multiple instances of the same part, you need only manipulate and mesh the original part; these features are automatically inherited by the dependent instances. Since you created only one instance of each part in this tutorial, you could have created independent part instances and worked with them just as easily. This would have allowed you to create partitions and assign mesh attributes at the assembly level rather than at the part level. You can make a dependent part instance independent by clicking mouse button 3 on its name underneath the Instances container in the Model Tree and selecting Make independent. In what follows, we assume the part instances remain dependent.

  1. In the Model Tree, expand Hinge-hole underneath the Parts container and double-click Mesh in the list that appears.

    Note:

    If the part instance were independent, you would instead expand the instance name underneath the Instances container and click Mesh in the list that would appear.

    Abaqus/CAE displays the hinge piece with the lubrication hole. The cube portion of the hinge piece is colored green to indicate that it can be meshed using the structured meshing technique; the flange with the lubrication hole is colored orange to indicate that it needs to be partitioned to be meshed using hexahedral elements, as shown in Figure 2. The partitioning procedure is described in Partitioning the flange with the lubrication hole.

    Figure 2. The flange with the lubrication hole cannot be meshed.

  2. Use the Object field that appears in the context bar to display the solid hinge in the viewport. Abaqus/CAE displays the solid hinge. As before, the cube portion of the solid hinge piece is colored green to indicate that it can be meshed using the structured meshing technique. The flange without the lubrication hole is colored yellow to indicate that it can be meshed using a swept mesh.

  3. Select the pin from the Object field in the context bar. Abaqus/CAE displays the pin in orange because it is an analytical rigid surface and cannot be meshed.

    Thus, the hinge piece with the lubrication hole needs to be partitioned to be meshed with hexahedral elements; the solid hinge and the pin require no further action.