x
Diese Website verwendet Cookies. Mit der Nutzung der Website stimmen Sie deren Verwendung zu. Weitere Informationen erhalten Sie in unserer Datenschutzerklärung.

USE OF FORMING LIMIT CURVE AS A FAILURE CRITERION IN MARITIME CRASH ANALYSIS

The crashworthiness of marine structures is one of the main area of interest of several parties active in maritime area. The ability of structural material to absorb mechanical energy without fracture, is a very important safety feature. For offshore structures, the general approach towards a fracture criterion is based on the Norsok standards. For inland waterways, it is based on ADN Guidelines. These standards were developed many years ago considering the technology of those years. With the increased sailing speeds and different materials now available to offshore structure manufacturers and shipbuilders, some limitations of these standards are being identified. One of these shortcomings is on the fracture criteria of deformed structures. Recent studies at TNO, focusing on vulnerability of an LNG tank, showed that in collisions the deformation of structures is much more complex compared to that of simple hull (shell) structures and requires more accurate fracture criteria. Especially not regarding the multiaxiality of the occurring strains explicitly, is seen as a serious drawback. In addition, knowing that nowadays different metals such as Stainless Steel, High Tensile Steel, Steels such as 460NL and 690QL are used, a fracture criteria that is valid for different materials at different conditions, even at cryogenic temperatures is needed. Therefore, we propose to use Forming Limit Curves (FLC), that is originally developed for forming of thin sheet metals for identification of fracture at crash analysis of maritime structures. FLC is generally obtained experimentally for different material types. In LS-prepost FLC can be used easily. The full length paper will include LS-Dyna results of an impacted 33 m3 LNG fuel tank study analyzed using FLC approach. Applicability of this method for crash analysis involving complex structures with thick walls will be opened to further discussions.