| Vacuum assisted resin transfer molding(VARTM)technology is an advanced low-cost and high-performance polymer composite molding process,which has the advantages of high fiber content,low porosity,low production cost and low environmental harm to the environment.It has been used in the preparation of wind turbine blades,which not only improves the performance of blades,but also meets the needs of energy saving,harmless and environmental protection.The main research goal of this paper is to apply fiber composite materials to the windward and leeward shells of blades.The basics of glass fiber composite wind turbine blades were analyzed by numerical simulation finite element simulation and mold and scaled down part test methods.The performance is studied to explore the advantages of VARTM in the process of preparing wind turbine blades.Based on the research on typical parts of wind turbine blades,this paper studies the process used to produce resin-based fiber composite parts and concludes a comprehensive law with a wide range of applications.Based on the above goals,this research mainly studies the content of the following three parts.In order to explore the infiltration rule of resin under the vacuum assisted molding of glass fiber and understand the infiltration process of resin in the porous media of glass fiber,using Darcy's law and mass conservation equation,introducing Hele-Shaw flow theory to establish the mold cavity pressure change model and basic control equation in the resin filling process,and to explore the influence of driving force on the filling process in the VARTM process,so as to achieve the purpose of simulating the filling results in advance by numerical calculation.On the premise of fully understanding the basic principles and process characteristics of vacuum-assisted transfer molding technology,the main factors affecting the filling time and filling quality were analyzed according to the mathematical model,and various factors and different defect types that affect the formation of defects were obtained.The results showed that vacuum pressure was the main power source of resin impregnated fiber preform.Vacuum pressure had a significant effect on resin filling time in the process of VARTM,while capillary effect on resin filling time in the process of VARTM was mainly determined by the degree of dehydration reaction during fiber pretreatment.The process of vacuum molding of the wind turbine blade shell was designed,including the selection of materials,the lay-up method and the design of the flow channel,etc.,the scheme of wind turbine blade filling was optimized,a variety of different process parameter combinations were designed,the location of flow channel layout was analyzed and calculated.Based on the finite element analysis software of resin filling,the resin filling process of wind turbine blade was simulated,and the resin filling process is observed flow behavior and filling quality,got the optimal filling scheme,made the blade filling molding speed fast,avoid defects,could greatly improve production efficiency and reduce production costs.Designed and manufactured blade molds that were scaled down,and established a VARTM process test bench,used the experimental equipment to prepare glass fiber wind turbine blade shell structural parts,respectively record the complete mold filling time,resin consumption and loss of different schemes,combined with simulation the results were compared and analyzed to observe whether the obvious defect parts of the experimental parts meet the cause of the defects in the simulation,and judged whether each molding scheme meets the process conditions and environmental protection conditions.Analyzed the reasons for the errors in the experiment and simulation results,proved the feasibility of the computer simulation process applied to the VARTM molding process.The process design could be applied to actual production,and the products with excellent performance and no obvious defects could be obtained. |
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