Shipping is constantly looking for new fuels that have as low environmental impact as possible. A fuel that has become increasingly popular is liquefied natural gas, known as LNG (Liquefied Natural Gas). It’s already used today in cruise ships, passenger ships and container ships.
In the risk analysis for the ships' panel structures that have an important structural function, one has in the design assumed that LNG leakage will very rarely occur and to some extent taken various measures to ensure that LNG does not come into contact with the panels.
There is currently a lack of knowledge about how an LNG leakage would affect the properties of the metallic material if it occurs at the same time as the ship is out in severe weather where it’s exposed to difficult wind and wave conditions. The purpose of the project has been to compare physical model experiments and results from computer-based simulations.
“With the right knowledge, models and numerical analysis technology, we can ensure that the design of panel structures in ships that are exposed to arctic or cryogenic temperatures meets the expectations and requirements they have concerning the loads that may occur” says Jonas Ringsberg.
The results applied with commercial software
The project's simulation models and results regarding buckling strength at arctic and cryogenic temperatures have already been applied with commercial software to help the industry develop revised guidelines for the design of ship structures exposed to these low temperatures. This in turn will lead to that ships that are now being developed having higher safety in the event of LNG leakage.
Tests in ICASS - unique research infrastructure
The physical tests were performed in a unique test facility in South Korea called The International Center for Advanced Safety Studies (ICASS) and are operated by the Korea Ship and Offshore Research Institute (KOSORI) located at Pusan National University in South Korea. With the collaboration, Chalmers has been included as a research partner, which means access to the unique facility. Something that pleases Jonas Ringsberg.
"It's very positive. The corresponding testing is not possible in Europe" says Jonas Ringsberg.
The Swedish Research Council project has the name "Fundamental research on the ultimate compressive strength of ship stiffened plate structures at Arctic and cryogenic temperatures" and received funding from the Swedish Research Council’s bilateral cooperation between Sweden and South Korea.