3D Printing-Oriented Porous Reef Structure Generation System

Artificial fish reef is a designed structure used to trap and multiply marine organisms,and it is an important facility for the development of marine ranching.The construction of marine pastures is the key to solving the contradiction between the sustainable utilization of marine fishery resources and the protection of the ecological environment,and it is of great significance to my country’s promotion of marine economic development and the construction of marine ecological civilization.The Ministry of Agriculture organized the compilation of the "National Marine Ranching Demonstration Area Construction Plan(2017-2025)" and made deployments for the development of marine ranching.It is particularly urgent to use 3D printing technology to improve the traditional way of building reefs.Using 3D printing technology,the artificial fish reef made of clay and concrete as printing materials has bio-compatibility.3D printing technology can realize from the generation of digital files to the manufacture of highly complex geometric shapes,and can meet the high requirements for functionality and economy in the development and exploration of artificial reefs.Among them,after experimental research and production practice verification,the most prominent functional and economic requirements are,first,a higher area per unit volume for marine organisms to attach,that is,higher space utilization;second,a more structured structure.It is complex,and it is necessary to provide a space that meets the habitat,growth and development of marine organisms.How to generate structures with high space utilization is the first challenge.In the 3D printing technology of clay and concrete as printing materials,due to the limitation of material properties,how to realize the printability of complex structures with high space utilization rate poses a second challenge in path planning.At the same time,the richness of the internal space and the response to complex conditions such as submarine currents also pose challenges to the design of artificial reefs.To address the above challenges,this paper proposes a 3D printing-oriented porous reef structure generation system.Mainly did the following work:1.Fully compare and select multiple structures and their mathematical models,select a complex porous interconnected structure with higher space utilization,and use a standardized mathematical model to generate the structure.2.A structure with rich diversity is designed to realize a variety of apertures in the same structure,providing a variety of spaces for the habitat,growth and reproduction of marine organisms.3.In view of the high requirements of clay or concrete printing materials on the continuity of the structural printing path,the printing path is optimized to achieve printability and avoid structural collapse caused by material viscosity and structural complexity.4.The self-adaptive deformation adjustment of the porous interconnected structure is realized,so that the shape of the artificial reef can meet the requirements of the influence of the seabed ocean current and the construction of the seabed landscape.The reef prepared by this system has been put into the fish reef and sea cucumber breeding experiment of Hainan University/State Key Laboratory of Marine Resources Utilization in the South China Sea.The experimental results show that the artificial reef with a porous interconnected structure has played a good role in the attachment and protection of sea cucumber seedlings,and the survival rate of young sea cucumbers has increased to 95%.The reef has been put into the waters of Yuzhizhou Island in Sanya to further test its bait attachment efficiency.This system will be continuously updated and iterated in order to contribute to the construction of marine ranches.