At present, the composite materials used in automobile manufacturing are mostly fiber-reinforced, or resin-based composite materials reinforced by woven fabrics and non-woven fabrics. Vehicles are exposed to external vibrations during driving, resulting in damage to internal parts. Therefore, transportation vehicles generally need to have better shock absorption. At present, in transportation vehicles, high-strength, high-elasticity, and heat-resistant composite boxes based on fiber-reinforced composite materials and PMI foam sandwich materials have been used.

Car spoilers are generally used to increase the grip of high-speed vehicle tires to improve fuel efficiency. However, the spoiler will vibrate under the influence of the high-speed air flow brought by the vehicle, and cause noise. Therefore, the rear spoiler of the car needs to be light in weight and have good shock absorption performance. Generally, the core layer of PMI foam is made of polymer foam quilt, and the two skins are made of heterogeneous materials, such as carbon fiber reinforced plastics and glass fiber reinforced plastics, which are combined by bonding. The sandwich layer composite material has the characteristics of light specific gravity and good shock absorption.

Therefore, in order to meet the requirements of light weight and shock absorption performance of automobile rear spoiler, a sandwich-layer composite spoiler was designed and developed using polymethacrylimide foam as the core material and carbon fiber reinforced composite material as the skin. This material is called carbon fiber reinforced sandwich composite material. In order to meet the lightweight and shock absorption requirements of the car rear spoiler, this research applies polymethacrylimide foam material and CFRP sandwich composite material to the spoiler, and designs a structurally safe PMI foam core CFRP Sandwich composite spoiler.

Its weight is much lighter than the traditional ABS/PC spoiler. Using reverse engineering and finite element analysis, the design scheme of carbon fiber laminate was obtained. When using five pieces of carbon fiber braid prepreg, the PMI-FCCSC spoiler is 28.9% lighter than ABS/PC spoiler, when using four-layer carbon fiber braid prepreg, it is 36.2% lighter, and when using three layers In the case of carbon fiber prepreg, it is 43.6% lighter.