舰船破浪中的强非线性砰击与颤振响应的耦合分析

High-speed and large vessels easily experience green water and slamming and whipping, when they are advancing in the severe sea. Accurate prediction of this complex phenomenon is significant for the seakeeping and safety performances of the vessels. The vessels are always encountered impact of green water and slamming simultaneously, when they are advancing in the nonlinear waves with large amplitude. Strongly nonlinear phenomena will also be occurred, such as wave breaking, splashing, and water-air blending. And this violent multiphase interaction involved in ship motion, slamming load, and whipping response of structure must be solved in a full-coupled way. Due to its complexity, so far all the present analysis not solved this strongly nonlinear problem accurately and it is usually solved by a separate way or by a weakly coupled procedure. In this proposal, a multiphase numerical wave tank based on the CIP(constrained interpolation profile) method will be developed to solve strongly nonlinear phenomena, such as, large-amplitude ship motion, slamming, water splashing, overturning and green-water impact. An FEM(finite element method) is used for analyzing the whipping response of the structure, and a full coupled hydroelastic numerical model is established for analyzing the ship motion, slamming load, and whipping response of the structure under the impact loads due to green-water and slamming. Finally, experimental and numerical studies will be carried out to analyze the influence of the seakeeping and safety performances of the vessels on the slamming load and whipping response. The effect of coupling the ship motion, slamming/impact loads and whipping response are investigated and concluded.

随着舰船的大型化和高速化，舰船破浪航行中的强非线性上浪、砰击与颤振响应问题变得更加突出。这一复杂物理现象的准确预报对舰船的航行性能、安全性能具有重要意义。舰船破浪航行过程中砰击与上浪往往是同时发生的，并常伴随着水体飞溅、水气掺混等强非线性现象，该过程是船体运动、砰冲击荷载和颤振响应三者之间的相互耦合过程。但由于问题的复杂性，目前仍没有很好地对这一强非线性的三维耦合过程进行准确的研究与分析。本研究将基于CIP方法建立固-液-气多相流数值水池模型求解船体剧烈运动、砰击飞溅、水气掺混等强非线性现象。采用有限元方法建立船体梁振动响应模型，并与数值水池模型进行融合，建立砰击与上浪联合作用下的船体运动、砰冲击荷载和颤振响应的全耦合时域分析模型。通过开展物理模型试验和数值研究，分析砰击特性与振动响应特性、及其对舰船航行性能、安全性能的影响机理，明确船体运动、砰冲击荷载和颤振响应之间的耦合作用机制。

随着舰船的大型化和高速化，舰船破浪航行中，尤其是集装箱等肥大型船舶的强非线性上浪、砰击与弹性响应问题变得更加突出。这一复杂物理现象的准确预报对舰船的航行性能、安全性能具有重要意义。砰击与上浪经常是同时作用在船上，且伴随着水体飞溅等强非线性现象。本研究将基于自编程代码CIP方法建立二维、三维的固-液-气多相流数值水池模型求解船体剧烈运动、入水砰击、水气掺混等强非线性现象。结合商业软件的有限元方法建立船体振型，并与数值水池模型进行融合，建立砰击与上浪联合作用下的船体运动、砰冲击荷载和振动响应的全耦合时域分析模型。为研究船舶的水弹性响应与砰击载荷，把船体分为多个分段（不同剖面），从简单到复杂、从二维到三维，展示了数值模型和物理实验研究。计算了二维楔形体和S175经典船型的不同剖面的入水砰击，与相应试验数据进行了对比验证。进行了海洋中固定或自由运动的浮体受到的波浪力和复杂自由液面抬高的计算模拟，对三维船模在波浪中所受砰击载荷及其运动响应进行了模拟。给出了高海况下船舶大幅运动的多相流数值模型、两分段（浮箱）、三分段（浮箱）的水动力性能研究、船体分段入水砰击研究、船体大幅运动与甲板上浪的时域模拟、大幅运动与波浪增阻的时域模拟及物理模型与数值模型的对比验证等研究。