Glass Fiber / Unsaturated Polyester Resin Laminates Impact Resistance

Glass fiber reinforced composite materials were widely used in the field of engineering because of their high specific strength and stiffness. But these composite materials are easy to suffer low energy impact during service, and also more sensitive to impact load. When the velocity is high, the composite laminates will be broken down; while the impact velocity is low, the damage will generate different forms, such as matrix cracking, fiber breakage and delamination. Most of the composite material damage caused is not all at once, often suffer several low-energy impacts before the material failure. The majority of composite materials have no obvious visual damage when suffered low-energy impact, but the laminated surface will generate superficial delaminate. It may create potential dangerous. The presence of internal damage can cause huge losses in strength and stifmess of composite material. So we should attach great importance to low-speed impact damage problems of composite laminates. .The impact resistance of glass fiber / unsaturated polyester composite laminates was studied in this paper. First, by using VARI (Vacuum Assisted Resin Infusion) molding technology, composite laminates were produced. Then the impact property of these composites was tested and analyzed. The impact mechanism of composites, the damage appearance after impact, the breakage damage characteristics and energy absorption during breakage process were expounded in detail. It also analyzed the impact resistance in deferent fiber volume fraction, deferent layer lay-up number and deferent construction glass fiber reinforcement. In particular, the impact resistance of four different layer lay-up design methods was analyzed. The results showed that the impact resistance of 0°/90°/0°/90°lay-up is better than the other three lay-up modes. The application in car of the impact performance of glass fiber reinforced composite material was introduced. The impact resistance of body material directly related to the safety of the personnel. So we should design a safer glass fiber reinforced composite material, when it suffers impact by external forces, the material can absorb some energy, resulting in deformation and security improvement. Finally, the composite laminates subjected to low velocity impact was simulated by finite element. The numerical simulation using transient analysis method, the change of stress field during the impact process was studied by transient analysis.