You can align the mesh to the top, middle, or bottom faces of the shell. To align the mesh to a reference surface, you can type an offset value. By default, the mesh is always aligned to the middle face of the shell.
The Shell Definition PropertyManager has the following options:
- Middle surface
- Aligns the mesh with the middle surface of the shell
- Top surface
- Aligns the mesh with the top surface of the shell
- Bottom surface
- Aligns the mesh with the bottom surface of the shell
- Specify ratio
- Aligns the mesh to a reference surface defined by an offset value that is a fraction of the total thickness. The image shows the meaning of the positive and negative offset values.
For example, to model adjacent shells with differing thicknesses such that their bottom faces coincide, you can create the two surfaces using the Bottom surface option.
Offset for shells is not available for large displacement analysis.