The dynamic response of an offshore jack-up unit to environmental loads has been investigated using a two-dimensional, non- linear finite element model. The model includes realistic representations o the wave loading, the geometric non-linearities of the rig legs and the complex non-linear effects of combined loads on the spudcan footings, Results are presented from a parametric study in which a typical jack-up unit was subjected to waves of varying height and period. It is shown that the accurate non-linear modelling of both the legs and the spudcan footings has a significant effect on the rig dynamics. The widespread practice of modelling the footings as simple pinned supports may be non-conservative for some sea states.
展开▼
