Technology Research On Hull Structure Direct Calculation Of Fiberglass Fishing Boats

Fiberglass fishing boat, as a new type of energy-saving and emission reduction fishing boat, had become a remarkable revolution in the history of the fishing boats' development. Relative to the wooden fishing boat, the fiberglass fishing boat has the advantages of lighter weight, faster speed, corrosion resistance, anti-storms and collision, better preservation performance, easier maintenance, longer service life, better economic efficiency, etc. At present, the fishing boats are almost made into fiberglass type in the world's major developed countries, such as the United States and Japan, while our country is relatively backward in this field. The fishing boats in our country, most of which are still wooden, become the bottleneck on the development of our fishery. In order to realize the construction of modernized fishery, enormous efforts should be paid in studying and developing the fiberglass fishing boat.Structure Direct calculation is an effective method in calculating the structural strength. Calculations followed the rules and components tests are the main means for the FRP fishing boats. The paper come from a national nonprofit industry research, had researched on the FRP materials, the fiberglass fishing boat and the key technologies of their FEM direct calculation. Throughout the whole article, the main research work is as the following aspects:(1) Summarized the characteristics of FRP materials, the mechanical properties of anisotropic materials and the method of finite element simulation of composite materials.(2) Summarized the key points in designing and building fiberglass fishing boat. Analyzed the form and structure features of the fiberglass fishing boat and their impacts on direct calculation. Discussed the energy-saving and emission reduction effect brought by the fiberglass fishing boat, which is also the evidence of that the wooden and steel fishing vessels would be replaced by the fiberglass fishing boat is of great feasibility and inevitability.(3) Combining with the structural characteristics of the fiberglass fishing boat, researches on the key technologies of the direct calculation on its cap-shaped reinforcing rib and the impact of the aggregate cross-section shape to the stress concentration at the roots. As the size of the cap-shaped reinforcing rib is big and usually has core, it can not be simulated by one-dimensional beams but by shell. Studies have shown that:the foam core can not afford the structure role and can be ignored when direct calculation, but the pine core must be built up; with the growing of the top angle, the stress of the roots reduced at the first and then increased quickly.(4) Researches on the key technologies of the direct calculation on the bulkhead with foam core. The paper built up a detailed model and a simplified model of a transverse bulkhead, composed their calculation results in the same loading and boundary conditions.