Evaluation of the Injury Risks of Truck Occupants Involved in a Crash as a Result of Errant Truck Platoons

Abstract

Platooning is an extension of Cooperative Adaptive Cruise Control (CACC) that realizes automated lateral and longitudinal vehicle control while moving in tight formation with short following distances. The truck platoons are expected to include at least five trucks with drivers in the first and the last trucks. This paper discusses the methodology and presents results of a single tractor-van trailer impact into a concrete barrier, which is a dedicated approach for a broader truck platooning implication research funded and supported by Safety through Disruption (Safe-D) University Transportation Center (UTC). First, full scale crash impacts were simulated with the LS-DYNA® software employing an existing tractor-van trailer FE model and a detailed model of a concrete bridge system. Impact criteria were those set in the Manual for Assessing Safety Hardware (MASH) standards, for a specific Test Level condition. The impact simulation of the tractor van-trailer against the concrete barrier was calibrated against the full scale crash test conducted by the Midwest Roadside Safety Facility (MwRSF) based on vehicle behavior. Calibration of the system was also assessed based on barrier damage after impact, which was achieved by utilizing erosion model of the barrier concrete, and plastic strains for the reinforcement components. Then, a previously developed truck cabin model, with inclusion of interior structures, was utilized to conduct simulations to assess occupant risks during the impact event. The motion of the truck cabin was then prescribed based on the displacement time histories of more than 8 nodes recorded in full crash truck-barrier simulations. The accuracy of simplified cabin motion relative to the full truck motion was verified against displacement time histories of a node set which include cabin nodes different than those used in prescribed motion. The injury risks of truck occupants involved in a crash as a result of errant truck platoons were evaluated using dummy and human occupant models representing a 50th percentile male. The occupant LS-DYNA models employed in this study were the HIII dummy and THOR dummy. The occupant models were setup in a seated driver posture and restrained using specific seatbelt restraint systems, which included a retractor, a pretensioner and Drings. The kinematic and dynamic measures included in well-defined injury criteria corresponding to various human body regions (e.g. HIC, Nij) were recorded and the occupant risks of injury were assessed based on injury curves published in literature. Additional simulations with the models developed in this study could help to understand if any roadside safety device improvements and/or platooning constraint modifications will be necessary before implementing truck platooning. 15th International LS-DYNA® Users Conference Occupant Modeling June 10-12, 2018 2 Introduction Platooning is an extension of Cooperative Adaptive Cruise Control (CACC) that realizes automated lateral and longitudinal vehicle control while moving in tight formation with short following distances. The truck platoons are expected to include at least five trucks with drivers in the first and the last trucks. It is unknown whether the capacity and adequacy of existing roadside safety hardware deployed at strategic locations is sufficient to resist a potential impact from a fleet of multiple trucks at high speed, which may occur as a result of errant truck platoons. It is also unknown how these impacting trucks might interact with roadside safety barriers after veering off the course of their platoon and what are the occupant risks associated with such impacts. In this study, a methodology was developed to simulate a single tractor-van trailer impact into a concrete barrier. The same methodology will be applied to examine how the existing roadside safety devices will perform under multiple impacts at close proximity during a potential impact from a fleet of multiple trucks at high speed, which may occur as a result of errant truck platoons, and to evaluate the injury risks of truck occupants.