This paper represents an experimental and theoretical study of dynamic characteristics of coupling resonance between a deep-water riser (DR) and a floating platform. The super long DR used for transporting offshore oil & gas is a high dimensional nonlinear pipeline, and the complex characteristics of coupling response is clarified when the heave amplitude or frequency of the floating platform changes. By using the method of reverse combination of test data (RCTD), a fluid-structure coupling model of DR acted by internal fluid, wave flow and floating platform is constructed. Truncated equivalent method and frequency search method are both adopted to deal with the 1300 m DR during the experimental study on mechanism of coupling resonance. Results of the scaled model tests show that higher order resonance is easy to occur when the DR transports high-density fluid, and amplitude jump phenomenon appears in the resonance region at the DR top, which is closely related to the internal fluid transported. According to the transformation of similarity relationship, the results of scaled model test and numerical calculation are consistent, and equivalent truncation method is convenient to study the large-scale nonlinear DR structures.

本文对深水立管（DR）和浮动平台之间的耦合共振动态特性进行了实验和理论研究。用于海上油气输送的超长DR是一种高维非线性管道，明确了浮动平台升沉幅值或频率变化时耦合响应的复杂特性。采用试验数据逆向组合（RCTD）方法，构建了内部流体、波浪流和浮动平台作用下的DR流固耦合模型。在耦合谐振机理实验研究中，采用截断等效法和频率搜索法来处理1300 m DR。缩比模型试验结果表明，DR输送高密度流体时容易发生高阶共振，且DR顶部共振区域出现振幅跳变现象，这与内部输送的流体密切相关。根据相似关系的变换，缩比模型试验与数值计算的结果是一致的，等效截断法便于研究大规模非线性DR结构。