Front underride protection devices: design methodology for heavy vehicle crashworthiness

Abstract

North American Heavy Vehicles contribute to a third of all road fatalities in Canada. Head on collisions are one of the most severe, as the mismatch of vehicle weight and sizing intensifies when a passenger vehicle is impacted. To improve crash safety, Front Underride Protection Devices (FUPDs) are a proposed solution to establishing a compatible collision between a passenger vehicle and a heavy vehicle. The European Union is among numerous administrations to regulate FUPDs, yet FUPDs are nonexistent in North America. Current regulations conform to European Cab-over Engine Tractors designs. Implementation of current regulations in North American conflicts with the widely driven Conventional Style Tractor due to the different design space for a FUPDs. This study builds on developing regulations for North America, and establishes a design methodology to developing and optimizing FUPDs for the Conventional Style Tractor enlightening the crashworthy importance of front underride protection devices to improving road safety. Advanced two stage optimization methodology was outlined to ensure industry targets are embedded with in the design to develop lightweight and cost effective devices. Recommendations for the modifications of the ECE R93 for Conventional Style Tractor are outlined; P1 load magnitudes requirements for FUPD stiffness should be increased from the regulated 80 kN to 160 kN to improve small overlap collisions. Regulated geometric parameters were recommended to have a minimal frontal contact height of 240mm, with ground clearance set between 350mm to 400mm. Geometric configurations were outlined and restricted to conform to the aerodynamic curvatures of the tractors bumper. After validation of the National Crash Analysis Center (NCAC) Toyota Yaris finite element analysis (FEA) model for side impact, the addition of a FUPD enhanced the survivability of passenger vehicle. The work achieved in enhancing the design methodology for industrial implementation and outlining regulations for North America.