真实海洋环境作用下，涡激振动（VIV）是低质量比海洋柔性管疲劳损伤的关键。目前工业及学术界对低质量比柔性管的研究相对匮乏，相关结构物设计存在严重的盲目性和安全隐患。本研究通过静水拖曳实验对质量比为 0.50 的柔性管进行了研究。采用模态叠加法重构了其位移响应，分析了其在顺流向（IL）和横流向（CF）的振幅、频率以及运动轨迹。结果表明，低质量比柔性管在IL方向的振幅出现了超上端分支，与 CF方向上观察到的振幅相当。此外，在 IL 和 CF 方向均未观察到频率锁定现象。IL和CF方向的频率比呈现出两倍关系，运动轨迹呈现出典型的“8”字形。这些发现有助于更好地理解具有低质量比柔性管的涡激振动特性，并为相关结构物设计提供有益的指导。

Under real marine environmental conditions, vortex-induced vibration (VIV) constitutes a critical factor contributing to fatigue damage in low mass ratio marine flexible pipes. Current industrial and academic research on low mass ratio flexible pipes remains relatively limited, resulting in substantial empirical approaches and safety risks in the design of related structures. In this study, a flexible pipe with a mass ratio of 0.50 is investigated by hydrostatic towing experiments. The modal superposition method was employed to reconstruct displacement responses, with subsequent analysis of amplitude characteristics, frequency features and motion trajectories in both IL and CF direction. Results demonstrate that the low mass ratio flexible pipe exhibits super upper branch amplitudes in the IL direction comparable to those observed in the CF direction. Notably, no frequency lock-in phenomenon was detected in IL or CF direction. The frequency ratio between IL and CF direction shows a two-fold relationship, and the trajectories show a typical “8” shape. These findings contribute to a better understanding of the VIV characteristics of flexible pipes with low mass ratios and provide useful guidance for the design of related structures.