Chalmers University crash tests safer front end designs

Researchers at Chalmers University of Technology in Sweden have developed a new truck front concept to significantly reduce fatal crashes in car-truck collisions. The new truck front comes after EU regulations for the maximum length of a truck were lifted.

It is widely accepted two modern passenger cars of the best safety standards should be able to cope with a collision at 80km/h without fatal consequences, said the researchers.

“Chalmers University research is intended to find ways to protect car occupants and truck drivers or collisions between trucks and cars. While the velocity is often moderate in truck-car collisions, the crash severity is high due to geometry, stiffness and mass incompatibility between the two vehicles," said Prof Robert Thomson of the vehicle safety division at Chalmers.

“The internal design of the new truck front is aluminium honeycomb. This is a structure composed of repeating hexagonal tubes made from aluminium foil. This is ideal for a lightweight, energy absorbing structure since about 97% of its volume is air.

“Aluminium honeycomb is used in many crash test barriers to provide a distributed force and absorb energy. By changing the foil thickness, we can change the force and deformation characteristics. It also has the manufacturing flexibility needed to create one-of prototypes and demonstrate proof-of-concept."

Crash tests on the new truck front were carried out by the Swedish transport administration, Trafikverket, and show better truck designs can reduce passenger car compartment deformations by 30% to 60%. The tests showed measurable results and clearly highlighted the new truck front made a big difference, said the researchers.

Steering, braking, and suspension components are at risk to be damaged if not protected. Protecting these components reduces the risk for subsequent crashes and even rollovers of the truck.

Fatal crashes between heavy goods vehicles (HGVs) and passenger cars account for between 14% to 16% of all car occupant fatalities in both the EU and US. The most common accident types in these collisions are head-on crashes on rural roads and rear-end crashes on highways. In more than 90% of traffic accidents involving HGVs it is the other party who dies, usually in a passenger car.

For a passenger car occupant to survive a head-on collision with a truck, the cabin in the passenger car needs to be kept intact. This is not something that is possible to guarantee today, even in the most modern cars, so the new truck front research aims to find the best ways to protect car passengers and truck drivers, in the future.

Thomson said: “We know  providing a distributed force over the struck car would allow its crash structures to perform more efficiently. From the first test, we could also see the energy levels observed were high and better energy absorption by the truck was needed.”