Impact energy absorption
As the energy absorbing structure, foamed aluminum is mainly used for the high specific strength of foam aluminum and the characteristics of stress platform in the σ-ε curve. The uniform aluminum foam has good energy absorption characteristics. The stress at the plastic deformation stage of the sigma curve is almost constant, and it absorbs energy in all directions. When aluminum foam is deformed, a large amount of energy is transformed into plastic properties, dissipating in heat form. It is a good component for impact protection. Foam aluminum is also a typical toughened material, which can prevent instantaneous catastrophic damage of cracks and defects in aluminum foam components. The springback deformation of aluminum foam under dynamic impact is very small. The springback rate of foam aluminum is less than 3%, while that of polyurethane foam reaches 15%, so it can effectively avoid two injuries in collision accidents.
The energy absorbed per unit volume of aluminum foam can reach as high as 6MJ/m3-9MJ/m3.. The structure of filling foam aluminum can significantly change the deformation behavior and fracture behavior of unfilled structure, and improve energy absorption ability. Audi, Volkswagen and Fiat motor companies have used aluminum foam filled tubes as shock energy absorbers for the front part of the engine to increase energy absorption capability and reduce impact load fluctuations.
| Impact energy absorption | |
| Making Composite Armor | The new composite armour is made of ceramic / foam aluminum / aramid fiberboard. In the middle or inner layer, 20mm thick foam aluminum material is used. The energy absorption effect of aluminum foam is used to disperse the penetrator and the armor projectile and prevent it from entering the interior. |
| Making Mine-proof Bottom Plate for Vehicles | Tanks, armored vehicles, heavy truck and so on the bottom of the V type, the outer armor plate, the middle layer is aluminum foam, the inner layer is aramid fiber board or steel plate, and mine. |
| Making Military Airdrop Packaging Box | At present, China's military airdrop packaging box is made by Hardin technology in the United States. The internal energy absorbing and damping materials are high-density plastic foam. The foam aluminum is used as an internal energy absorbing and damping material. The energy absorption and shock absorption capacity is increased by more than 10 times, that is, the safety of airborne equipment and ammunition is increased by more than 10 times. |
| Making Explosion-proof Deck for Ships | Deck deck with armor plate / foam aluminum plate / steel composite structure, deck strength increased by more than 2 times, anti blast, Anti Ballistic ability increased by more than 2 times. |
| Making Car Bumpers | The aluminum foam is used as a sandwich for making bumper cars. It has the function of absorbing kinetic energy of impact. The thickness of the aluminum foam core plate is generally 20mm, the density is about 0.6g/cm3, and the foam aluminum is deformed aluminum alloy. This bumper represents the world's overall development trend. Audi A8 has been used, BMW, Mercedes-Benz, Honda and other companies are also developing applications. |
| Making foam aluminum body | The automobile body is made of aluminum foam filled with aluminum foam, the stiffness is increased by more than 2 times, and the damping and anti-collision ability is increased by more than 3 times. |
