水流作用下重力式网箱浮架结构的动力响应研究

Study on the dynamic response of float collar of gravity cages subject to water currents

近年来深水网箱养殖设施得到了广泛的应用,浮架作为网箱结构的重要组成部分,其安全性对网箱的设计至关重要。基于有限单元法采用SHELL单元建立了浮架结构的荷载-变形数值模型,对水流作用下浮架的应力和变形进行了数值模拟,并开展物理模型试验对该数值模型进行验证。结果表明,该数值模型可以准确模拟浮架的变形,采用该数值模型,分析了不同流速条件下浮架的变形和应力,数值模拟结果显示:随着流速的增加,浮架的变形和应力逐渐增加。相同流速条件下,注水下潜后,浮架的应力和变形能够显著减小;因此,在强流条件下,可以采用浮架注水的方式,使浮架处于下潜状态,以改善浮架结构的变形和应力分布。

The offshore culture cage has been widely applied in the open sea recently. Floating collar is an important component for the fish cage structure,and the safety of floating collar is very important for the design of fish cage. The numerical model of floating collar was built by using the SHELL element based on the finite element method,the stress and deformation of the floating collar in current were simulated,and the numerical model were verified through the physical model experiments. The results showed that the numerical model could accurately simulate the deformation of the floating collar. Based on the numerical model of the floating collar,the stress and deformation of the floating collar under different water velocity were analyzed. The numerical simulation results indicated that the stress and deformation of floating collar were increased gradually with the increase of the velocity. The maximum deformation and stress of the floating collar in the floating condition was significantly larger than that for the floating collar in the submerge condition. In conclusion,the deformation and stress distribution of floating collar under high water current could be improved obviously when the floating collar was injected with water to make it be in submersible condition.