With the need for energy conservation and the development of the automotive industry, there is an urgent need to upgrade electric vehicles. The battery and its housing is one of the crucial technical elements.
Electric vehicle battery boxes require materials with high strength, lightweight, and excellent corrosion resistance, and carbon fiber composites just meet all the requirements. Carbon fiber composites have high specific strength (ratio of tensile strength of material to density) and specific modulus (ratio of elastic modulus of material to density), and its specific strength is 5 times that of steel, carbon fiber, and epoxy resin The composite density is 1.6kg/m3, and the carbon fiber material also has excellent corrosion resistance and flame retardancy.
The carbon fiber woven fabric of the battery box adopts T300-3K and T300-12K, the two kinds of fabrics are mixed, and a total of 10 layers of carbon fiber plain weave and resin are designed. When laying layers, there are the following precautions: the balance of the laying angle, the quantity requirement of the same laying direction, the symmetry of the laying, the deviation of the angle between the laying layers, and the limitation of the maximum number of continuous laying layers. The battery box parts adopt the method of 10 layers of plain weave cross-laying, and the laying angle is [0°/45°/0°/45°/0°/0°/45°/0°/45%/0 °]. The weight of the carbon fiber battery box designed by this layer is only 12kg, and the overall weight is reduced by 3.5kg, which is 22% compared to the previous weight reduction, and its mechanical properties are good.
The design of the carbon fiber battery box also needs to consider the shape and arrangement of the battery module, combined with the position of the power battery on the body. The shape of the battery box is designed to be close to a square box structure. The main structure layer is made of carbon fiber cloth and supplemented with resin. Metal joints are used at the connection, and structural glue is used to connect the metal joints and the main structure layer. . Metal fasteners are used for connection between the battery module group and the box body. In order to increase the strength and modality of the parts, the battery box uses convex and concave ribs similar to hat-shaped ribs to strengthen the structure. In view of the characteristics of continuous fiber composite materials, the convex and concave ribs of the carbon fiber reinforced structure are designed with equal thickness.
After simulation analysis, it can be seen from the results that the carbon fiber composite battery box fully meets the requirements in terms of structural mode, mechanical impact and structural fatigue
