Study on motion transfer rule and extreme dynamic response of SCR’s top-end heave excitation

Abstract

As one of the most critical vessel motion, heave motion will lead to the great tension at the top end of a steel catenary riser (SCR), and can also result in the compression buckling and large bending moment in the touchdown zone (TDZ). The purpose of this study is to investigate the motion transfer rule of top-end heave excitation along catenary risers and explore the underlying correlation between the riser dynamic amplification and heave motion characteristic. Extensive numerical calculations are well conducted by a developed mathematical model for riser dynamic based on the rod theory in the time domain. According to the results obtained from the proposed methodology, it can be found that the heave induced acceleration is the dominant factor on the dynamic top tension, and the dynamic tension and bending moment in the TDZ are mainly driven by the velocity of top-end heave excitation.