STRUCTURAL DAMPING BEHAVIOUR OF UNBONDED FLEXIBLE RISERS

Measurements of self-damping of an unpressurised flexible riser specimen are reported. The effects of structure configuration, mode order, displacement amplitude and temperature on structural damping are discussed and representative damping values are provided. Coulomb damping owing to the slippage between various component layers is found to be the dominant factor in the total damping. Temperature is shown to have a significant influence on both damping value and bending stiffness of a flexible riser. The experimental results reported herein can be used to predict damping values of full scale marine risers.