Swedish researchers develop new truck front to mitigate accidents

A new truck front-end concept is designed to mitigate the consequences of collisions between trucks and passenger vehicles. It is based on aluminum honeycombs, whose energy-absorbing structure is intended to reduce the impact of accidents, especially for the occupants of passenger vehicles. Researchers at Chalmers University of Technology in Sweden have developed the new truck front-end by taking advantage of the EU regulations changed in 2019 regarding the maximum length of trucks.

Crash tests by the Swedish Transport Administration, Trafikverket, have shown that improved truck designs can reduce deformations in the car area by 30 to 60 percent, according to Chalmers University. This also decreases the risk of injury and possibly death for the vehicle occupants.

Trucks can be deadly

In both the EU and the USA, heavy commercial vehicles are involved in 14 to 16 percent of all fatal car accidents. In over 90 percent of traffic accidents involving trucks, the other party, usually in the car, dies. In most cases, these are head-on collisions on country roads or rear-end collisions on highways, where the truck crashes into the back of the preceding car.

While two modern cars with the highest safety standards can survive a collision at 80 km/h without fatal consequences, the situation is different for collisions between trucks and cars. Due to geometry, stiffness, and mass incompatibility, severe consequences can occur even at moderate speeds, as the car’s passenger compartment deforms accordingly.

This is where researchers at Chalmers University step in. They looked for ways to keep the passenger compartment as intact as possible to protect both the car occupants and the truck drivers in the future.

Honeycombs to buffer

Cars and trucks are already designed so that in the event of an accident, discrete structural elements such as bumpers, energy-absorbing beams, and passenger compartment frames either absorb energy through deformation or remain intact. Both protect occupants from more serious injuries. However, it is repeatedly shown that localized structures rarely interact as designed. The research team at Chalmers University of Technology therefore designed the new truck front based on a honeycomb structure. It aims to improve the collision process. The team wanted to demonstrate design principles that manufacturers can then interpret and adapt.

"We know that a distributed force over the impacted car would allow its crash structures to work more efficiently. In the first test, we could already see that the observed energy levels were high and required better energy absorption by the truck. Another challenge was to deflect the car from the truck's forward path," says Professor Robert Thomson from the Vehicle Safety Department at Chalmers University of Technology.

New EU Regulations Create Space

The interior design of the new truck front consists of aluminum honeycombs. This is a structure made up of repeating hexagonal tubes of aluminum foil. There is already experience with such aluminum honeycombs, as they are used in many crash test barriers to provide a distributed force and absorb energy. This is ideal for a light, energy-absorbing structure, as around 97 percent of its volume consists of air, explains Professor Thomson.

"By changing the foil thickness, we can alter the force and deformation properties. It also has the manufacturing flexibility required to create a prototype and demonstrate the 'proof-of-concept.'

Less Impact in an Accident

The new truck front was tested by the Swedish Transport Administration Trafikverket at Autoliv's test track in Vårgårda. It became clear that the new truck front makes a significant difference. The modified truck design can reduce the deformations of the car interior by 30 to 60 percent, which lowers the risk of injury for the car occupants. The deformation of the truck in sensitive areas was also reduced, improving the safety of the truck driver and the cargo. Steering, braking, and suspension components are at risk of being damaged if not protected. The protection of these components reduces the risk of subsequent accidents or even rollovers of the truck.