Enhancement of tensile strength of embedded parts in carbon fiber-reinforced plastic/aluminum honeycomb sandwich structures for vehicle

Sandwich-structured composites are common in lightweight, low-load-bearing applications. The connective strength of embedded parts determines the reliability of joints between the composite and other parts. Therefore, enhancing the connective strength between embedded parts and the composite is important. Carbon fiber-reinforced plastic (CFRP)/aluminum honeycombed sandwich-structured composites include two fields: one between the carbon panels and the honeycomb reinforcement, and the other between the carbon panels and vertical surfaces of the embedded parts. Focusing on these fields, we studied the tensile strengths of embedded parts through three reinforcement schemes: adding CFRP of different heights between the sides of a cylindrical embedded part and the honeycomb and between the vertical surface of the part and the carbon panel; varying the roughness of the vertical surfaces of the cylindrical embedded parts; and adding different heights of aramid fiber-reinforced plastic (AFRP) to the vertical area between the carbon panels and the embedded parts. All tested reinforcement schemes improved the carrying capacity of the embedded parts. The greatest strengthening effect was obtained by adding AFRP asymmetrically to the embedded part, which reinforced areas both between the carbon panel and honeycomb and between the embedded part and honeycomb; and the strengthening effect increased with increased bonding height.