Research On The Key Technology Of Carbon Fiber Composite Material Molding Of Automobile Front Floor

Carbon fiber reinforced resin composite has long been known as the “hope ofmaterial”,because it has high strength, low density, good heat resistance, low thermal expansioncoefficient, excellent corrosion resistance and low radiation performance. Carbon fibercomposite material is used in aerospace, bridge, building, highway, fan blades, sportsequipment, auto parts. But for the high manufacturing cost, complex process, it has notbeen widely used, especially in the civil composite materials. Therefore, rapidprototyping technology of carbon fiber composite material automobile parts is particularlyimportant.In this paper we research the technology of vacuum assisted resin infusion (VARI) ofautomobile front floor molding of carbon fiber composite material, and the properties of thematerials, and some parameters. Using vacuum assisted resin injection(VARI) molding process,the suitable curing process for the composite automobile front floor and beams is80℃/2h+110℃/2h+140℃/2h with the biphenyl-A resin system. This paper study on mechanicalproperties of domestic and imported T300plain weave carbon fiber, and determined to use theimported T300plain weave carbon fiber to manufacture front floor board and beam. With thetesting of the relationship between viscosity and temperature we get the best resin injectiontemperature50℃.The selection of injection port and outflow position in the VARI process is veryimportant, This use the numerical simulation method to determine the optimum resin injectionport and outflow position. The permeability of fiber material is also a very important parameter inthe process of numerical simulation, this paper deduced formula of Darcy’s law, and getthe permeability of fiber reinforced6.2E-11m2. Finally, we simulate the VARI process of moldfilling of automobile front floor by the software PAM-RTM, obtained the optimum injection portand outflow position,and get the filling time982s. Tt`s very close to theactual filling time820s. Comparing with the traditional "trial and error" method the numericalsimulation method shorten the cycle of the experiment. After the experiment, we tested the front floor. The weight of the composite automobile frontfloor and the spar which were fabricated by the VARI, were13.6kg. Compared to the metal frontfloor of automobile, weight was reduced by49.63%.The stiffness of the automobile front floorand the spar which were fabricated by the VARI molding process, were comparative with that ofthe metal one. Results showed that the model frequency of the white automobile body wascomparative with that of the metal ones.