Work

Dynamic response and fatigue behavior of a mining riser with variable wall thickness under irregular waves and currents

Year: 2026

Type: article

Abstract: The structural integrity and dynamic performance of deep-sea mining risers are affected by waves, currents, and vessel motions. This study proposes a deep-sea mining riser consisting of four segments with wall thickness decreasing stepwise with ocean depth to enhance structural stability and reduce costs. A time-domain lumped-mass model is developed incorporating irregular waves, linear shear currents, and vessel motions. The dynamic responses of the segmented riser are compared with uniform-wall-thickness risers under varying wave heights and periods, followed by fatigue analysis. The results indicate that the segmented riser had considerably lower axial tension and higher mechanical performance than the uniform-wall-thickness risers did, indicating it is suitable for deep-sea mining. Fatigue evaluation indicated that cumulative damage was more considerable when waves were higher and the peak wave period was shorter. In addition, the dynamic response analysis revealed abrupt changes in bending moments at the connections between the third and fourth segments.

Source: Ships and Offshore Structures

DOI: 10.1080/17445302.2026.2657588

Authors: Kunlong Cheng, Chen Huang, Lihui Wang, Sakdirat Kaewunruen, Jian Zhang

Institutions: Jiangsu University of Science and Technology, Jiangsu Ocean University, University of Birmingham

Language: English

Topic: Offshore Engineering and Technologies

Subfield: Ocean Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Industry, innovation and infrastructure

Open Access status: green

Funders: Government of Jiangsu Province, Natural Science Foundation of Jiangsu Province for Distinguished Young Scholars