How to design stiffeners

Stiffeners are crucial components that reinforce a ship's structure. This article provides an overview of the stiffener design process.

Stiffeners enhance the structural integrity of plate parts by distributing loads and preventing buckling. The design process involves determining the best fitting type, size, and placement of stiffeners based on factors such as plate dimensions, loading conditions, and practical considerations.

Designing stiffeners in MasterShip

This video explains how to draw stiffeners and demonstrates the applicable functionalities in MasterShip. Here below are also some the best practices listed from the engineering perspective:

• Drawing the stiffener: The commands SHIPPARASTIFFENER, SHIPCREATESTIFFENER, SHIPFACEPLATE, and SHIP3DSTIFFENER can be used to create stiffeners and faceplates.

All these commands offer libraries of pre-defined elements and profile types and allow for parametric variation. This is what we at MasterShip call Template Oriented Modelling (TOM).

• Use end-details on stiffeners: Stiffener end-details can be useful for production purposes or for creating a smooth connection to another structural body. 

• Allow for bending: When a stiffener needs to be bend, or modified in any other way, a overlength of about 50mm is usually desired.

The dialogue window, that pops-up while drawing a stiffener, gives support to these best practices. The window provides a library with a variety of stiffener types to choose from. The library contains a lot of typical stiffener end-details too, and you can set a start- and end gap or an overlength.

It is also possible to define your own stiffener types using the MasterShip Organiser.

• Use pipes or staff material around mooring holes, coamings, etc.: This helps to avoid sharp edges and improves stiffening. 

• Consider maximum staff lengths: Most industrial sizes of staff material is 6 or 12 m. The command SHIPSPLITPART can be used to split stiffeners too.

• Saving time and ensuring consistency: So called 'parametric stiffeners' can be copied to other positions. This comes in handy when there is a repetitive pattern. For example with a stiffened plate field. This can be done using the command SHIPCOPYSTIFFENER and 'reference lines'.