Abstract: In order to find out the reasons for the poor bending stiffness performance of plastic fishing raftand find a way to solve the problem of easy deformation. in this study, three factors affecting the bending stiffness were analyzed and compared with traditional mariculture cages: frame section, elastic modulus of frame material, and the span of the floating ball tied under the frame. Results show that there is little difference in the moments of inertia between the side section of the plastic fishing raft frame and the wooden frame of the traditional aquaculture cage, that is, the geometric properties of the cross-sectional structure are similar. The span of bound floating balls under the frame of plastic fishing raft is basically the same as that of traditional mariculture cage, and is not the main factor leading to the difference of bending stiffness. The main factor affecting the bending stiffness difference between the two is the material performance, because the elastic modulus of HDPE is about 8.18% of Hemlock which is the traditional cage frame material. That means due to material characteristics, plastic cages have insufficient rigidity compared to traditional aquaculture cages, which could easily affect the production safety. Several methods are recommended to improve the rigidity of HDPE mariculture cages, such as improving structural performance through optimization, modifying HDPE to increase its elastic modulus, and adding auxiliary rigid facilities to achieve the purpose of increasing bending stiffness.

Key words:  , Plastic aquaculture cages；frame；ending stiffness；cage culture；marine cage

摘要： 为研究高密度聚乙烯（HDPE）近海养殖网箱（俗称塑胶渔排）框架易变形的原因，从而找到提高改进的方法，解决易变形问题。本研究分析了影响网箱框架抗弯刚度三要素，即框架截面、框架材料弹性模量和框架下方捆绑浮球跨距，并与传统海水养殖网箱进行比较。结果显示：HDPE近海养殖网箱框架边与传统养殖网箱的木质框架边的截面惯性矩差异性很小，截面结构几何性能相近；HDPE近海养殖网箱与传统养殖网箱木质框架边下方捆绑浮球跨距基本一致，不是导致刚性差异的主要因素；影响两者刚性差异的主要原因是材料性能， HDPE的弹性模量约为传统养殖网箱框架材料铁杉木的8.18%；研究表明：与传统养殖网箱相比，HDPE近海养殖网箱刚度有所不足，容易对安全生产造成影响；生产应用中需要适当提高HDPE近海养殖网箱的刚度，如通过优化框架结构、对HDPE进行改性，提升其弹性模量、增加辅助刚性设施等方式达到提升刚性等，以满足安全要求。

关键词: 塑胶网箱, 框架, 抗弯刚度, 网箱养殖, 海水网箱