Car-to-Truck Frontal Crash Compatibility

Abstract: For the last five years, are average of 38 500 people have been killed each year inEurope in road traffic accidents and, even if Heavy Goods Vehicles represent only 1%of the vehicle registered, they have been involved in more than 5000 fatal accidents in2009. Among these accidents involving trucks, 65% involved the truck front.The severity of these crashes can be explained by the large mass difference betweencars and trucks that inevitably leads to higher deceleration pulses for the passengercar; most of times followed by major deformations of the car passenger compartment.In the worse frontal crash cases, the car ends under the truck.To reduce the risk of trucks overriding passenger cars and reduce the crash severity,so-called Front Underrun Protection Systems have been developed and are nowcompulsory on new trucks in Europe. The efficiency of these systems has been provedby different studies but it has also been shown that they could be even more efficientif their energy absorption could be increased for instance by increasing the deformation length.The purpose of this thesis work was therefore to quantify the possible crash severityreduction, mainly for the car occupants, from an additional truck frontal structure incase of frontal crash between cars and trucks and to make recommendations on a newfront structure of heavy trucks that can have an injury reducing potential for caroccupants. In this study the length, the stiffness and the basic design of this new truckfront structure have been investigated. The study has been made mainly using FiniteElement simulations but also using analytical calculations.The results confirm that the use of a longer energy absorbing structure in front of thetruck would decrease the crash severity for the car occupants while experiencing afrontal crash with a truck. The critical impact speeds are increased since the new truckstructure is absorbing much more energy than current Front Underrun ProtectionSystems. Because of the new frontal structure load distribution, the forces that need tobe carried by the truck front structure are also lowered.