In order to preliminary investigate structural response of stiffened panel due to slamming impact, two series of fluid structure coupling analysis is carried out using a new fluid structure interaction (FSI) methodology of Incompressible Fluid Dynamics (ICFD) . ICFD is the method where structure and fluid are modeled as both Lagrange methods.
Firstly, slamming impact of a sphere is analyzed with ICFD and SPH methods respectively and compared with experimental and analytical results. Acceleration, slamming force and pressure are compared and discussed in detail.
Secondary a fixed stiffened flat panel of offshore structure subjected to slamming impact is investigated as a part of the ISSC II.1 benchmark study. Effect of mesh size is investigated. Analysis results are compared with existing ALE method  as well as other results within the framework of ISSC II.1 benchmark study.
In both studies, structure is modeled by elastic-plastic and by rigid respectively. By comparing these two results, effect of structural rigidity on the slamming pressure as well as slamming force is investigated.