A major problem of the predominantly flat fronts of trucks used in Europewith respect to accidents involving vulnerable road users are the kinematics of the vulnerable road user after the impact. Contrary to car versus vulnerable road user accidents the flat truck front pushes the vulnerable road user to the road rather than lifting him. This effect causes a high risk of a run over. The main idea of the presented safety device is to change the flat front to a tapered shape deflecting the vulnerable road user sideways by using the impact impulse. The achieved deflection reduces the risk of a run over. The tapered truck front has been designed and analysed within the EC funded APROSYS integrated project. For a principal investigation the tapered shape is realised by an add-on structure mountable to the front of a reference truck. Hence, a direct comparison of the flat and thetapered shape is possible. Regarding a practically relevant application of this safety concept with respect to technical and economical feasibilitythe tapered shape has to be implemented directly in the cab design. During the development phase of the new front structure a large number of design versions are generated and assessed. The resulting final principal shapeis compared to the basis truck in various numerical simulations with different accident scenarios, pedestrian models and parameter settings. Due tothese results it can be concluded that a convex truck front significantlyreduces the risk of a run over. It is most effective in accidents with higher speed (> 20 km/h) and the additional deformation space reduces the contact forces at the primary impact. In this regard it has to be discussed whether the implementation of passive safety devices in trucks should implicate a revision of the vehicle length regulation. The full text of this paper may be found at: http://www-nrd.nhtsa.dot.gov/pdf/esv/esv21/09-0458.pdf For the covering abstract see ITRD E145407.
Abstract