Abstract:
Improper operation during the deployment of artificial reefs (ARs) can result in some problems, such as collision damage, drop site faraway from target spot, etc.. In this paper, the deployment process of a frame-type AR in still water environment is studied. Based on the hydrodynamic model during subsidence and the colliding model between the AR and seabed, the existing impact force formula is amended, and the overall motion equations are developed. The numerical method is used to solve the ordinary differential equations to obtain the velocity and the impact force with different seabed stiffness. The results show that the impact force increases with the increase of stiffness. The multi-body dynamics software ADAMS is used to simulate the deployment process of the AR in different initial postures, and the strength analysis is carried out based on the finite element software ANSYS Workbench. The results show that the larger the initial angle is, the smaller the steady falling velocity is achieved; when an edge collides with the seabed the maximum impact force reduces compared to a surface, but it produces greater stress; and the maximum stress occurs in the middle of the colliding edges. This work can be a reference for the scientific design and deployment planning of artificial reefs.
Key words: artificial reefs, deployment, dynamics, simulation
摘要： 为解决不当的人工鱼礁布放操作导致的鱼礁碰撞破坏、布置点偏离目标地点过大等问题，对静水环境下框架型人工鱼礁布放的动力学过程进行了研究。基于人工鱼礁下落过程的水动力学模型、鱼礁与海底接触碰撞模型，对现有碰撞力公式进行合理修正，建立了人工鱼礁布放过程的整体动力学方程；采用数值方法对动力学方程进行求解，得到鱼礁下落速度以及不同海底底质条件下的着底冲击力。分析表明，海底底质越硬，着底冲击力越大。采用多体动力学软件ADAMS对鱼礁在不同初始姿态下的布放过程进行模拟，采用有限元软件ANSYS Workbench对鱼礁结构进行强度分析，结果表明，鱼礁初始姿态倾斜角度越大，下落达到的稳定速度越小；棱着底的最大冲击力比面着底的要小，但产生的应力更大；最大应力发生在着底棱的中部。本研究可为合理规划人工鱼礁的布放和人工鱼礁的设计提供参考。
