State of the Art
In small to medium size workboats single skin extruded aluminium panel are used for the superstructure and the deck houses. The single skin panels are either welded on top of the web frames or are running through the cut-outs in the web frames. When welded on top of the web frames relatively short weld lengths are achieved that might arise strength and fatigue issues if large shear forces are transmitted through the frames. Welding of the single skin panels to form an assembly introduces weld distortions. In addition to visual appearance, the weld distortions can deform the deckhouses of a relatively low stiffness. Thermal and fire insulation of the structures is time consuming as the panels are first insulated in between the stiffeners and secondly on top of the stiffeners.
Objective
The development of the design for lightweight and space-efficient extruded sandwich panels for the deckhouses of the small crafts/workboats which include the integration of the new panel system concept into the design and production environment and the development of procedures of joining.
Solution
A novel solution is sought in form of double-skin aluminium sandwich panels or composite sandwich panels. A solution based on composite sandwich panels allows less distortions during assembly and flush final surface, thus allowing to decrease the time for insulation. Moreover, the comparison of technical solutions has shown that the weight saving up to 30% can be achieved when using lightweight panels. In order to analyse the practical production issues, a detail design was developed for a smaller structural assembly – a sunroof for a river boat. The main function of the sunroof is not only to provide shelter from the sun and the rain but also to fulfil several technical requirements and provide technical functions, such as a support, charging rails for charging system, support for the LED lights, hatch for engine maintenance, etc. The demonstrator has been produced during the project.
Potential
There is a wide application potential especially for numerous small shipyards in Europe which produce a huge number of small vessels, often for local markets.