考虑水介质作用的船冰碰撞结构损伤机理研究

Ships sailing in the Arctic route is often under threat of icebergs and floes inevitably, which makes the collision accident between ship and ice more likely to occur. Though China is a nation close to the Arctic and it is the largest shipbuilding country, research on the key basic problem of ship structure safety under ice load is still very weak, which restricting the promotion of polar ship research and development ability..Structural dynamic response and damage mechanism research of ship-ice collision in water is the key scientific problem concerning the safety of ship structure. This project adopted the RANS equation,the improved two phase flow fluid volume function and model test method to forecast the transient load before the collision between ship and ice in the water, which decoupling the ship-water-ice coupling problem. The constitutive relationship with strain rate as the parameter adaptive change factor is considered,the ice material model used for numerical simulation, the quantitative analysis model of broken ice body and the numerical simulation method of ship-ice collision were set up; The dynamic response rules of hull structure were obtained by the numerical simulation calculation; At last, the collision test of grillage model and ice was conducted, which compared to the simulation one in order to verify with each other. And a measurement and analysis method of the model test of ship-ice collision was put forward at the same time.On the basis of it,the damage mechanism of ship-ice collison in water was revealed. It provide theoretical basis for the structural crashworthiness design for the polar ships.

航行于北极航区的船舶不可避免地受到浮冰及冰山的威胁，易发生船冰碰撞事故。虽然我国是一个近北极国家，但对极地船舶的抗冰载荷结构安全等关键基础问题的研究还相当薄弱，极大地制约了我国极地船舶研发能力的提升。.考虑水介质作用的船-冰碰撞结构响应及船体结构损伤机理，是事关船舶结构安全性的关键科学问题。本项目拟采用RANS方程和改进的双相流VOF(流体体积函数)以及模型试验方法对水介质中船-冰碰撞前瞬间的载荷进行预报，为船-水-冰三者耦合问题解耦；计及本构关系以应变率为参数而自适应改变的因素，建立准确反映冰体力学特征的冰体材料数值模型及船-冰碰撞数值仿真方法；通过数值仿真计算，获得船舶结构动态响应规律；最后开展船体板架与冰体的碰撞试验对仿真结果进行验证，同时提出一套船-冰碰撞模型试验的测量及分析方法。基于以上研究，揭示水介质作用下船-冰碰撞结构的损伤机理，为进行极地船舶的结构耐撞性设计提供理论依据。

航行于北极航区的船舶不可避免地受到浮冰及冰山的威胁，易发生船-冰碰撞事故。虽然我国是一个近北极国家和世界第一造船大国，但对船舶的抗冰载荷结构安全等关键基础问题的研究还很薄弱，极大地制约了我国极地船舶研发能力的提升。.计及水介质作用的船-冰碰撞结构响应及船体结构损伤机理，是事关船舶结构安全性的关键科学问题。其中，获得准确的船-水-冰耦合载荷和建立科学的冰体材料模型，是接近真实结果的必要条件。本项目主要研究内容包括：采用RANS方程及模型试验方法对水介质中船-冰碰撞前的瞬间的载荷进行预报，为船-水-冰三者耦合问题解耦；建立用于数值仿真的冰体材料模型、冰体破碎的定量分析模型及船-冰碰撞数值仿真方法；通过数值仿真计算，获得船舶动态响应规律，揭示水介质作用下船-冰碰撞结构的损伤机理；开展船体板架与冰体的碰撞试验，对仿真结果进行验证，提出一套船-冰碰撞模型试验的测量及分析方法。.本项目经过四年的工作，按照既定计划开展研究和实践，主要取得了如下成果：解析了船-水-冰三者耦合作用力，将预加水压力预先施加在船体及冰体表面，用以代替水介质的作用，简化了耦合计算，可以提高计算效率20%；在大量数值仿真的基础上，建立了准确的冰体材料模型及船冰碰撞数值仿真方法，计算结果与文献试验数值误差在10%以内；模拟真实船冰碰撞场景，建立船-水-冰三者耦合模型，计算获得了考虑水介质作用的不同工况下船-冰碰撞结构损伤模式和结构响应规律，获得了45o角度时对船体肩部损伤最大，同时获得了船体结构破坏以划割、屈曲、失稳为主要模式；通过实施了船体板架模型与冰体碰撞试验，将试验结果与数值仿真结果对比，误差在15%以内，验证了数值仿真方法的可靠性，同时揭示了水介质中船-冰碰撞结构损伤机理。