Authors: J.A. Romero; A.A. Lozano-Guzmán; E. Betanzo-Quezada; G.M. Arroyo-Contreras
Addresses: Faculty of Engineering, University of Querétaro, Río Moctezuma 249, San Juan del Río, Querétaro, 76800, Mexico ' National Polytechnic Institute, CICATA Queretaro Unit, Cerro Blanco No. 141. Colinas del Cimatario, Santiago de Querétaro, 76800, Mexico ' Faculty of Engineering, University of Querétaro, Centro Universitario, Queretaro, Queretaro, 76000, Mexico ' Faculty of Engineering, University of Querétaro, Centro Universitario, Queretaro, Queretaro, 76000, Mexico
Abstract: According to road safety standards, the cargo must be secured to the carrying vehicle in such a way that it does not shift or fall, setting performance measures addressing specific acceleration levels that the cargo restraint system must withstand. For a braking manoeuvre, the mandatory acceleration level is 0.8 g. On the other hand, improved stopping distances are being demanded, involving accelerations on the order of 0.52 g. In this paper, a dynamic model is proposed to assess the braking performance of a cargo vehicle, as a function of the cargo securement method and pavement roughness. Results suggest that transient accelerations greater than 0.8 g can be attained during the braking manoeuvre, as a result of the cargo-vehicle decoupling, provoking that the braking forces be exerted on a diminished mass. A value of 1.1 g is recommended as a new mandatory braking acceleration level that the cargo securement method should withstand.
Keywords: cargo securement; vehicle braking; braking performance; pavement roughness; road safety; cargo-vehicle interaction; tiedowns; road safety standards; braking acceleration level; stopping distance; performance measures; dynamic modelling; braking forces.
International Journal of Vehicle Performance, 2016 Vol.2 No.4, pp.353 - 373
Received: 24 Sep 2014
Accepted: 30 Aug 2015
Published online: 19 Oct 2016 *