不规则波和流下的重力式网箱水弹性响应研究

摘要

文章对重力式网箱在不规则波和流作用下的水弹性响应分析进行了研究,通过有限元方法建立实尺度网箱模型并对网箱的运动和变形进行了分析.在数值模型中,通过非线性弹簧单元和Truss单元来模拟锚链和渔网结构,通过若干耦合的梁按照"浮力分配法"来计算浮圈的瞬时浮力.基于这个计算模型,文中充分研究了当网箱处于波流载荷下,浮圈的各阶弹性体模态所占权重.结果显示,当有义波高增大时,在垂直方向上会激发出更多的浮圈弹性体模态,而流则主要影响水平方向上的刚体模态.%In this paper, the hydroelastic response of a gravity cage exposed to irregular waves and current was analyzed.A full scale net cage bulit by the FEM was introduced to further study the cage's motion and deformation. In the numerical model, nonlinear spring elements and truss elements were used to simulate the mooring lines and the net, respectively. Furthermore, the 'buoyancy distribu-tion'method was adopted by simulating the floating collar with several coupled beams in order to calculate the instantaneous buoyancy force acting on the collar. On this basis, when the net cage is subjected to wave-current flows, the dynamic response of the floating collar, the modal contribution to the collar's deformation from each mode shape were carefully studied.The results show that more flexible modes will be aroused in the vertical direction when the significant wave height increases;while the current will have a great contribution to the rigid-body motion in the horizontal direction.