You use conventional shell parts to model structures in which the
thickness is significantly smaller than the other dimensions, and you define
the thickness in the
Property module
when you create the section.
In contrast, you assign continuum shell elements to solid parts,
and
Abaqus
determines the thickness from the geometry of the part. From a modeling point
of view continuum shell elements look like three-dimensional continuum solids,
but their kinematic and constitutive behavior is similar to conventional shell
elements. For example, conventional shell elements have displacement and
rotational degrees of freedom, while continuum solid elements and continuum
shell elements have only displacement degrees of freedom. For more information,
see
About Shell Elements
and
Choosing a Shell Element.
Figure 1
illustrates the differences between a conventional shell and a continuum shell
element.
The general procedure for modeling continuum shells in three-dimensional
space involves the following steps:
In the
Part module,
define the solid geometry.
In the
Property module,
assign a shell section to any solid regions to which you will assign continuum
shell elements in the
Mesh module.
You must specify the thickness of a shell section; however,
Abaqus
uses this thickness only to estimate certain section properties, such as
hourglass stiffness.
Abaqus
uses the actual thickness, based on the element nodal geometry, during the
analysis. If the thickness of the solid region varies along its length, you
should provide an approximate value of the thickness. For more information, see
Using a Shell Section Integrated during the Analysis to Define the Section Behavior.
In the
Mesh module,
query the mesh stack orientation. If necessary, assign a stack orientation so
that the continuum elements are aligned consistently from the bottom to the top
of the stack. See
Applying a mesh stack orientation,
for more information.
In the
Mesh module,
assign a continuum shell element type to the region, and mesh the region with
hexahedral or wedge elements. These are the only elements that can be stacked
to form a continuum shell mesh.