The Preliminary Study Of Boundary Conditions In Frp Boats` Structural Fem Analysis

The industry of fiberglass boats in our country takes a rapid development at present. With the diversification of PRP materials, the performance improving continuously, the designers are constantly introduce various new hull structure in order to meet the aesthetic needs of the market and fulfill with reducing hull weight and manufacturing costs, so the current structural design methods on fiberglass hull cannot meet the need.1,Meaning and purpose of the studyFinite element methods can simulate complex structure and get more accurate result, therefore the finite element method to check the hull strength of FRP is the better choice at present. However, in the field of ship, while taking the design of ship structural and the of process structural strength of the verification, the boundary condition for steel ship have a more complete theory and methods. As for the fiberglass boats, due to the properties of materials and a variety of structural forms, the boundary conditions for satisfying the finite element structural calculations in steel ship are not suitable for the requirements of the analysis that finite element calculate on FRP hull structure. Therefore, the analysis of boundary conditions is in urgent need during the process of applying the FEM software to analyze the hull structure.2,Current status and development trend at home and abroadThe application of ANSYS in the area of composite materials at abroad is much earlier than the domestic application, therefore it has more extensive range of applications. Its range of applications involves many aspects of the design in composite materials, including fiber reinforced plastic materials. Using the commercial software package ANSYS analysis in cylindrical coordinates by using the glass fiber and foam sandwich of laminated sandwich plate helps reduce component weight. In 1995, France, Grando J, who use the ANSYS finite element simulation of glass fiber - epoxy resin composites were studied them. In 1998, the Italian Buccella C on advanced composite materials were two-dimensional stress analysis, solving the implicit and explicit solution, the two solution methods and the results were compared with finite element software package ANSYS calculated results Were compared. In 2000, France et al Labed N infinite boundary layer composite material structure has been optimized the thickness direction, and as one-dimensional structure of composite materials. In 2004, the United States, Prabu SB et al for the SiC volume fraction and fiber diameter of 6061A1/SiC Composites stress / strain of the finite element study.In the country, ANSYS widely used in various industries, especially in the field of composite materials has been widely used. Beijing University of Technology, KANG et al resin composite laminated steel sheet The new lightweight composite materials were studied, application of ANSYS finite element software to simulate the resin composite sandwich plate bending of light during the distribution and change the wrong momentum Law, and the stress, strain and displacement distribution in the flat section of the analysis. Northwestern Polytechnical University, Ma Zhijun, who uses ANSYS finite element analysis software, SCS-6 SiC/Ti-24A1-1 1Nb glass fiber materials, residual stress was simulated, focusing on analysis of fiber arrangement effects on the residual thermal stress.3,Content of the study1,Based on the analysis of fiberglass boats , the paper deals with layer unit to laminated structure and sandwich structure of fiberglass boat, which has the value and practical guidance for carrying out the direct calculation of structural strength in fiberglass boats.2,On the analysis of the cabin in different boundary constraints and the data of stress-strain conditions. It calculates stress-strain conditions in the relative position of the cabin in different strain. Compared to the data of the cabin obtained in the same loading state, imposing by different boundary constraints.4,Methods of the studyIn the paper, the result is applying by much experiment. First of all selecting the whole boat loading state in the arch to the basic condition, and imposing the simple constraints on the neutral axis of the head and tail of the ship, finally obtaining the data based on the condition. Compared to the data of the cabin obtained in the same loading state, imposing by different boundary constraints. Analyzing the data of the cabin imposed by different boundary constraints, adjusting these boundary constraints, its data is similar to the whole ship.5,Results of the studyTo the application requirements of FRP finite element structural calculation, the paper discusses about boundary conditions of finite element analysis based on the platform of ANSYS. The method practice the flexibility and effectiveness of finite element model test ,it also has the practical significance for the follow-up fiberglass boats of this model in finite element method to determine the boundary conditions. Applying by practicing continuous testing the finite element model of fiberglass boats in the boundary conditions, the conclusions are listed as follows: 1,In this paper, applying to parametric technology, changing the material properties of FRP boats, load and boundary conditions, attributes to spring element, I take a specific practice to achieve the parameters modeling of the finite element.2,First of all selecting the whole boat loading state in the arch to the basic condition, then imposing the simple constraints on the neutral axis of the head and tail of the ship, finally obtaining the data based on the condition. Compared to the data of the cabin obtained in the same loading state, imposing by different boundary constraints. Analyzing the data of the cabin imposed by different boundary constraints, adjusting these boundary constraints, its data is more similar to the whole ship.