Study On Equivalent Of Main Components And Frame Selection Of Fiberglass Reinforced Plastics Fishing Vessels

Fiberglass reinforced plastic fishing boats are a new type of energy saving and emission reduction boats, which is seen as a significant revolution of fishing craft. However, the design of FRP fishing vessels in China continues to use the similar method employed by steel fishing vessels, which ignores the designability of fiberglass, leading to the ingnorance of the light and high strength characteristic of glass fiber buried. This thesis focuses on the research of a 36.6 meters FRP fishing boat based on the theory of finite element analysis, including the study on the cap type girder and structural form selection. In order to design a frame structure of FRP fishing vessels which not only meet the requirements of strength and rigidity, but also can fully exhibit the mechanical properties of FRP, the following work has been completed:(1) The engineering elastic constant required for the calculation of th e thin plate structure was discussed based on the theory of composite materials. The accuracy and feasibility of the theory of engineering elastic constants for calculating the structural strength of FRP sheet, analyzed by Patran on computing, were verified by comparing the three-point bending test results and numerical solution of three-point bending test.(2) The typical structure of FRP boats was analyzed, including the study on the influence of core on the mechanical properties of cap-type girder and the feasibility by using the equal sectional dimension in the Patran software of beam element to equivalent simulating the cap-type girder, which simplified the whole ship building process of the finite element model and improved the computational efficiency.(3) Two kinds of hull structural forms of FRP fishing boats were designed, namely transverse framing and longitudinal framing under the conditions of same mass. And verification of the strength of the whole ship was conducted along with combined framing. Considering the influence factors of mechanical properties and manufacturing costs of three kinds of hull structural form of the FRP fishing boats, the longitudinal framing has good engineering reference value.(4) Under the precondition of the structural strength and rigidity of the fishing vessel, taking the weight of the whole ship as the objective function, the framing FRP fishing boat was optimized in order to make full use of the mechanical properties of FRP and achieving the lightest, which provides a scientific theoretical basis for the performance evaluation and design of FRP fishing vessels.