Shapes: Curved plates

Figure: Some example curved plate shapes

Curved plate shapes are particularly suited to modelling bellmouths, although they are not restricted to this application. The curved plate shape is similar to the cylinder, in that it is a possibly hollow solid of revolution; it differs in that the radius of the shape may vary smoothly between the ends, and in that the angle of revolution may be less than 360°.

Shape is hollow

If ticked then the shape is hollow: it has both inner and outer surfaces, and its wall has a thickness. The middle illustration above is not hollow, whereas the other two are.

Orientation

This consists of three angles, azimuth, declination and gamma. The azimuth and declination of the principal axis define the shape's orientation relative to the connection axes. The gamma value defines the rotation of the shape about its own axis, so is only relevant when the included angle of revolution is less than 360°.

Included angle of revolution

The curved plate is a solid of revolution. A value of 360° gives a complete revolution as shown in the first two of the three figures above. Smaller values can be used to model partial or cut-away curved plates – for example the right-most figure above has an included angle of 90°.

Thickness

If the shape is hollow then this value specifies the wall thickness, measured normal to the shape's principal axis.

Note: You may need to use an artificially large value for thickness in order to avoid objects passing through the wall of the shape during the statics calculation.

Profile

The overall shape of the curved plate is given by a table of diameter, or radius (if you edit one, the other will be updated accordingly), against distance along the shape's principal axis or centreline. The radius is the radial distance (i.e. in direction normal to the shape axis) from the axis to the surface. If the shape is hollow then the profile defines the radius to the inner surface. If the shape is not hollow then the radius is that to the outer surface. Cubic Bessel interpolation is applied to generate a smooth profile.

The remaining curved plate data are common to all geometric shapes and are described under the shape data and drawing topics.