Shell Definition

The Shell Definition PropertyManager is used to define the thickness of thin and thick shell elements. You can also define a shell as a composite for static, frequency, and buckling studies.

Type

• Thin. Uses the thin shell formulation.

In general use thin shells when the thickness-to-span ratio is less than 0.05.

• Thick. Uses the thick shell formulation.

• Shell Thickness . Specifies the shell thickness. Lets you type the thickness and select units.

• Composite. (Available only for surface geometries in static, frequency and buckling studies). Defines the shell as a composite laminate.

Composite Options

Available only when you model composite shell surface for static, frequency, or buckling studies. You can apply these options to a shell or a group of shells through multiple selection.

• Sandwich. Selects the sandwich composite formulation.

• Total Plies. Sets the total number of plies for the composite laminate. Available only when Sandwich option is cleared.

• Symmetric. Specifies a symmetric layup of laminate about the laminate mid-surface. Available for editing only when Sandwich option is cleared.

• All Plies Same Material. Applies the same material properties defined by Select material option to all plies.

• Rotate 00 Reference . Redefines the stripes on the composite shell so that the earlier 900  ply angle now corresponds to 00  ply angle. The option applies to all faces of a shell definition.

• Unit . Specifies the unit for the ply thickness.

• Ply angles relative to ply 1 . Defines the ply angles of the stack relative to the orientation of the first ply. For example, if ply angle 1 is 450 and the absolute value of ply angle 2 is 600, then the relative value of ply angle 2 with respect to ply angle 1 is 150. The first ply angle is always absolute. The angle cells of the subsequent plies turn yellow.

• Composite shell plies. Specifies the Thickness, Angle, and Material for each ply in the table.

• Ply: Angle: . Lets you move the slider to set the ply angle for selected ply in Composite shell plies table. Alternatively you can type the value for ply angle in Composite shell plies table. Valid angle values are between -90 to 90 degrees.

The Ply: Angle: sets angle definition for all faces of the part and does not allow local control for an individual face.

• Surface Mapping. Uses the surface mapping technique based on the UV coordinates of a surface to determine the zero degree ply angle reference. By default, the U direction represents the 0 0  reference. You can align the 0 0  reference with the V direction using the Rotate 00  Reference option.

• Planar Mapping. Uses the planar mapping technique to project a common zero degree reference to a group of faces or surface bodies. The projection direction is normal to the selected plane or reference face. This option works best on planar faces. You can select a reference face or edge to define the projection direction for the Selected Reference option.

• Save stack to file. Saves the composite stack information to files with .csv or .txt extensions.

• Load stack from file. Populates the saved composite stack information. Lets you edit and use the information to define the composite shell.

Composite Orientation

Available only when you model composite shell surfaces using the surface mapping option. Composite orientation options allow you to control the ply orientation of each face separately.

• Body/Shell. Available only when multiple shells are selected from the Simulation study tree. Allows you to select a surface body from the drop menu to which orientations are applied.

• Selected Entities . Selects a face to which material orientation changes apply.

• Mirror Orientation. When toggled, the direction of the blue arrow of triad is flipped. As a result ply angle definition changes from counter-clockwise direction to clockwise direction or vice versa.

• Rotate Orientation. Rotates the stripes by 90 degrees along the surface of the ply. This option is similar to the Rotate 00 Reference but allows control for individual faces.

Offset

The offset options allow you to control the position of the shell mesh relative to its surface. The offset options are also available for composite shells.

• 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 offset value ranges between -0.5 and 0.5.

Related Topics

Shell Mesh

Shell Modeling

To Define Composite Shells