Foam core stiffens steel
01.11.2011
Aalto University's researcher Jani Romanoff developed a lightweight ship deck structure. Rigid, foam-filled steel panel lightens the ship, and lowers its centre of gravity.
Researcher Jani Romanoff bends a sheaf of copy paper into a S-shape. Power is not needed. Another, still wrapped pack does not bend in researchers hands.
This is also how a closed, foam-filled steel structure works. Filling the steel panel with special foam makes it up to seven times more rigid. At a same time, weight of the structure will increase only 15 percent.
- Foam effectively prevents local bending of the surface and the core plates. Sandwich panels stiffness is increased multiple times, says Romanoff.
Today, ships decks are made from heavy duty, 6 millimeter thick steel plate, stiffened with welded vertical beams having height 100mm. Using a lightweight foam-filled sandwich structure, thickness of the deck is less than 5 centimeters instead of over 10 centimeters.
- The weight saving may be as much as 40 percent. Thinner decks means lower center of gravity. Ship becomes more stable, naval architect Romanoff lists the benefits.
Jani Romanoff has studied the foam filling for over 10 years. Finally this summer, persistence was rewarded. In recent SUTERA-project researchers found a feasible filling method and –materials. Stiffness of the structure improved several-fold. Also corrosion resistance proved to be excellent in tests where panels were immersed in seawater for two years.
Romanoff says that the new structure is ready for use for example as lift decks on car ferries.
- The space and weight saving would give a significant competitive advantage.
In order to be suitable for all the ship's decks and bulkheads, researchers still have to resolve how the panels are connected together.
- Welding of the closed structures is difficult, says Romanoff.
Aalto University Marine Technology laboratory: http://www.tkk.fi/Units/Ship/
Jani Romanoff’s scientific publications www.tkk.fi/Units/Ship/Personnel/Romanoff/index.html
Contact info:
Jani Romanoff
Professor of Naval Architecture (Acting)
Department of Applied Mechanics / Marine Technology
Tel. +358 9 4702 4171
jani.romanoff [at] aalto [dot] fi
Aalto-yliopiston laivalaboratorio: http://www.tkk.fi/Units/Ship/
Jani Romanoffin tieteelliset julkaisut: www.tkk.fi/Units/Ship/Personnel/Romanoff/index.html
Yhteystiedot
Jani Romanoff
Professor of Naval Architecture (Acting)
Department of Applied Mechanics / Marine Technology
Tel. +358 9 4702 4171
jani.romanoff [at] aalto [dot] fi (jani.romanoff@aalto.fi )
Text: Petja Partanen, Tarinatakomo
Teksti Petja Partanen
