The Study Of Composite Materials Trough RTM Processing And Modal Analysis Of Auto Front Floor

Based on the Composite material auto front floor structure processed through resin transfer moulding (RTM).this paper mainly studied the property of bisphenol F epoxy resin cured with anhydride system as well as the toughening modification to improve the toughness of resin system. The relationship of liquid resin toughening agent content with the rheological property, curing property, mechanical property, and thermal property was studied.It was showed that resin toughening agent F-100is inert.In the curing process,it only changed its physical form.and had no effect on the curing reaction apparent activation energy and reaction series. When the ratio of toughening agent F-100and Bisphenol F epoxy was5:100between10:100,the toughness of resin system was increased greatly while the modulus and glass transition temperature(Tg) had little loss. When the ratio of toughening agent F-100and Bisphenol F epoxy was15:100,the toughness of resin system was increased even more,but the modulus and Tg dropped a lot. By comparing, the ration5:100was elected as the ultimate RTM resin system.and Taiwan li12K carbon fiber woven fabric as reinforcing fabrics. Composite laminated plate was prepared by the RTM processing,and the mechanical properties, thermal properties and micro defects of the composite materials were also studied. The5:100resin system had a low viscosity and a long pot life. The tensile strength of the resin system cured products was up to80MPa, the flexural strength127MPa, the glass transition temperature (Tg)112℃, when the cure schedule was110℃/2h+130℃/4h.And the tensile strength, the flexural strength, the interlaminar shear strength and Tg of the composite material was up to843.0MPa,615.1MPa,49.1MP and112℃by DSC characterization.The third chapter mainly studied the permeability characterization methods of reinforcing fabric.A transparent mold was designed, through which the resin flow in the fabric can be clearly observed. Based on the theory of the Darcy’s law,the unidirectional flow method and radial flow metod were used to measure permeability of fiber reinforcing-materials. The influence of fluid viscosity and different fiber volume content on the permeability were studied.The result was that, With the increasing of volume fraction of fiber fabric, the permeability is rapidly reduced; the influence of viscosity on the permeability is small.With the increasing of fluid’s viscosity, the permeability tended to decrease, but not obviously; While the measured result of the radial flow method is lower than the one of the unidirectional method.The fourth chapter mainly analysed the structure of the floor by finite element simulation. Because of the complicated metal structure of traditional auto front floor,there are some parts on the floor can’t be processed by RTM integrated molding of composite materials.The original model must be simplified and redesigned.By the finite element modal analysis of the structure before and after its simplification and redesign.the stiffness of the simplified composite material model significantly dropped compared with the metal mode. The thickness of the composite material auto front floor must be increased to avoid the loss of stiffhess.lt was showed that,when the thickness of the composite material auto front floor model was as twice as the metal model.the lost stiffness can be compensated, and the weight of the composite material front floor decreased57.6%.