单恒年1，董国海2，许条建3
（海岸和近海工程国家重点实验室，大连理工大学，辽宁 大连，116024）

摘要：利用离岸网箱进行水产养殖近年来受到了越来越多的重视，离岸区域海况条件恶劣，浮架结构的安全性对于网箱的设计具有极其重要的意义。为研究网箱浮架结构在动态波浪荷载作用下的动力响应，采用有限单元法利用PIPE单元建立了浮架的数值模型，并根据物理模型试验结果对该数值模型进行验证，发现有限元模型的计算结果与模型实验结果吻合较好。基于该模型，重点分析了网箱的连接构件数量和个别锚绳发生断裂对浮架动力响应的影响，得到了浮架结构连接处的应力值、变形值以及浮架的变形模式图。结果显示，数值模型能较好地模拟网箱浮架的受力和运动响应；连接构件数量增加时，浮架的应力和变形将会减少；当下游同侧两根锚绳同时断裂时浮架应力和锚绳力最小。研究表明，动力特性是结构优化分析的重要依据，24套连接构件的浮架应优先使用。
 

关键词：浮架；动态响应；应力；变形；数值模型；物理模型
 

Structural analysis of floating collar for gravity cage system in the open sea
SHAN Hengnian1，DONG Guohai 2，XU Tiaojian 3
（State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian 116024, China）
 

Abstract:Fish culture in the offshore fish cage has been received more and more attention recently, while there are bad sea conditions in offshore areas, so the safety of floating collar is very important for the design of fish cage system. To study dynamic response of floating collar under the wave loading, the numerical model of floating collar was built based on finite element method using the PIPE element, and a series of physical model test were conducted to validate the numerical model, and the results showed that the calculated results agreed well with the test results. Then the numerical simulation was performed to analyze the effects of the number of clamps and the breakage of mooring line on the dynamic response of floating collar. Finally the stress and deformation value of the connection points and deformation models of the floating collar of floating collar were obtained. The results indicated that the numerical model could accurately simulate the deformation of floating collar and the mooring line tension force. In addition, the stress and deformation value of floating collar was decreased with the increase in the number of clamps, and the stress value and mooring line force were decreased significantly to minimum when two mooring lines on the same side break. In conclusion, dynamic response is an important basis for structure optimization and analysis, and floating collar with 24 clamps is recommended.
 

Key words: floating collar; dynamic response; stress; deformation; numerical model; physical model