Determination of damping ratio distribution along riser pipe using optimal feedback gain

摘要

This paper shows that optimum distributions of damping devices alonga catenary riser differ between in-plane and out-of-plane components ofvibration. Transverse dynamics of catenary riser pipe was combined withoptimum control theory to compute the optimum distribution of dampingratio. We defined a cost function measuring magnitude of vibration andamount of the damping devices, and calculated damping ratiodistributions so that the cost function is minimized. The difference ismarked especially if we intend to decay a specified mode of vibration.