Creating a Stiffener Using a Curve as a Support

This task explains how to create a stiffener using a curve as a support.

The technique used here requires you to draw a spline on the surface, and create the stiffener using it. You can also use a line as long as it is placed on the surface. The result shown here was produced using the Generative Shape Design (GSD) application. However, you can use other methods. To use GSD, you need to see documentation for that product. However, certain general principles are explained below.

1. In this example, the user wanted to create a stiffener located at a certain distance below the top edge of the hull - say 10 meters. Using GSD, the user:
  • Created a series of curves on the hull. NOTE: When you are creating a spline, it is recommended that you select the hull as the support, not the shell plate, in case the hull design changes later in the design process.
  • Created points on the curves, located at 10 meters from the top edge of the hull.
  • Created a spline that follows the points. The image below shows the curves, with points placed on them. The hull has been hidden.

2. After you have created the spline, open the Object Design workbench. Select the hull and click the Stiffener button. The Stiffener dialog box displays.

3. Make the appropriate selection in the Category field, in this case Shell Side Longitudinal Stiffener.
4. Select the shell plate in the Plate field.
5. Select the spline in the Support field.
6. Make your selections in the other fields as described in Creating a Deck Longitudinal Stiffener or Creating a Deck Transverse Stiffener.

NOTE: Although the Offset and Angle fields are available when creating a stiffener on a curve, neither affects the result. A stiffener on a curve is always created with an Offset of 0, and the angle is always Normal to Plate regardless of what the dialog box displays. When creating more than one stiffener at a time, if you select a mix of curve and plane for supports, the Offset and Angle fields are available, but ignored for stiffeners on a curve. If the Offset is changed to a non-zero value on a stiffener on a curve during edition, the operation will be ignored, and a warning is shown.

7. Click OK to create the stiffener. The image below shows a section of the hull with the stiffener placed on it. The hull has been angled to allow you to see the curvature of the stiffener.

The image below shows two stiffeners placed on a hull.