DYNAMIC RESPONSE OF THE CATENARY RISER IN DEEP-SEA MINING SYSTEMS ¹⁾

With a finite element model, the dynamic response of the catenary riser of deep-sea mining systems under the action of the ocean current and the motion of the surface vessel is simulated. The results show that the maximum equivalent stress and the maximum displacement of the catenary riser change periodically with a phase difference of half a period between them. When the surface vessel moves to the highest position, the displacement of the catenary riser reaches the maximum. The maximum equivalent stress and the maximum displacement of the catenary riser increase with the increase of the displacement amplitude of the surface vessel and decrease with the increase of the period. In addition, the effect of the displacement and the period of the motion of the surface vessel on the equivalent stress of the catenary riser is greater than that on the displacement.