DAMPING OF FIXED OFFSHORE PLATFORMS

Damping of fixed offshore platforms is discussed on the basis of fullscale measurements of dynamic response of gravity platforms and jacket platforms. It is shown how the measured data indicate that the damping of these structure is highly non-linear in a way which gives that the commonly applied linear damping models are non-conservative. Furthermore, the sources of the non-linear damping is discussed and, finally, some comments are given on the possible effects of such damping to extreme dynamic response and fatigue life of deepwater platforms. .