doi: 10.52899/24141437_2026_02_195
UDK: 531.391.1:532.5.011

Nonlinear forces and second-order motion amplitudes acting on a systematic series of ships

Семенова В. Ю., Альбаев Д. А., Сунь Х. .
Article language:
Citation Link: Semenova VYu, Albaev DA, Sun Hechen. Nonlinear Forces and Second-Order Motion Amplitudes Acting on a Systematic Series of Ships. Transactions of the Saint Petersburg State Marine Technical University. 2026;5(2):195–206. DOI: 10.52899/24141437_2026_02_195 EDN: XIFCSV

Annotation

Background: Numerous studies have demonstrated the significant influence of second-order nonlinear forces on the resulting motion amplitudes. Most calculations were performed for individual ships, but no studies have been conducted on the influence of individual ship parameters on the values of nonlinear forces and the resulting motion amplitudes. Therefore, studying the effect of changes in ship length on second-order nonlinear motion amplitudes is a pressing issue. Aim: This study aimed to investigate the influence of changes in the length of ships of a systematic series on nonlinear motion amplitudes. Methods: The method of integral equations was used to calculate nonlinear forces and the amplitudes of nonlinear motions caused by them. Results: Analysis of the obtained results showed that reducing ship size leads to increased amplitudes of nonlinear transverse motion types and an expansion of the zone of nonlinearity influence. Under irregular wave conditions, reducing ship size leads to an increased influence of nonlinear factors at sea state 7.8. Conclusion: The paper presents the results of calculations of nonlinear motion amplitudes and wave drift forces for a systematic series of ships under regular and irregular wave conditions, taking into account second-order nonlinear forces. A study was conducted on the influence of the main dimensions of the ship on nonlinear motion amplitudes. Keywords: nonlinear forces, small parameter method, motion amplitudes, wave drift forces, integral equation method

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