Hydrodynamic Behaviour of a Floating Linkspan: A study on wave responses
Examensarbete för masterexamen
Applied mechanics (MPAME), MSc
Maritime transport is an important part of global trade. Ro-Ro transports standing for roll-on-roll- off is a an important part of maritime transport. Ro-Ro transports is closely related to the concept of linkspan. Tide and waves can make access to quay difficult. A linkspan, as a solution is a facility to provide a good connection between shore and ship for discharging and loading. In this thesis firstly, a hydrodynamic study is performed on an integral tank linkspan to understand how environmental factors such as wave at extreme tide levels (Highest and Lowest Astronomical Tide) in combination with extreme loading conditions (Full and Empty) affect the motion of the linkspan. Secondly, a load mapping approach is performed to study the wave impacts from a structural strength perspective. This approach is based on using inertia information from the hydrodynamic or the structural model, since these are not the same. The feasibility of the load mapping approach is also assessed. Heave and pitch motion is studied in head sea (180 wave heading angle) while roll motion is studied in beam sea (90 wave heading angle) in the hydrodynamic analysis. The results have shown that at small wave periods the pitch motion is unfavorable at the highest tide level. Maximum roll motion is obtained at smaller wavelength to structure length ratio in comparison to the heave motion. The load mapping reflects the wave situation fairly good and the wave impact can be reflected in the deformation contour-plots. It is found that the maximum stress in the load mapping part is obtained at the hinges. It is also found that by using inertia from structural model a more realistic result in terms of deformation is obtained.
potential flow , Source Distribution Method , Ansys Aqwa , Response Amplitude Operator , Finite Element Method , incident wave , diffraction wave , radiation Wave , wave spectra , heave , pitch , roll.