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Torsional stiffness properties were developed for both a 53-foot box trailer and a 28-foot flatbed control trailer based on experimental measurements. In order to study the effect of torsional stiffness on the dynamics of a heavy truck vehicle dynamics computer model, static maneuvers were conducted comparing different torsional stiffness values to the original rigid vehicle model. Stiffness properties were first developed for a truck tractor model. It was found that the incorporation of a torsional stiffness model had only a minor effect on the overall tractor response for steady-state maneuvers up to 0.4 g lateral acceleration. The effect of torsional stiffness was also studied for the trailer portion of the existing model.

In 2007, a software model of a Roll Stability Control (RSC) system was developed based on test data for a Volvo tractor at NHTSA's Vehicle Research and Test Center (VRTC). This model was designed to simulate the RSC performance of a commercially available Electronic Stability Control (ESC) system. The RSC model was developed in Simulink and integrated with the available braking model (TruckSim) for the truck. The Simulink models were run in parallel with the vehicle dynamics model of a truck in TruckSim. The complete vehicle model including the RSC system model is used to simulate the behavior of the actual truck and determine the capability of the RSC system in preventing rollovers under different conditions. Several simulations were performed to study the behavior of the model developed and to compare its performance with that of an actual test vehicle equipped with RSC.

Validation was performed on an existing heavy truck vehicle dynamics computer model with roll stability control (RSC). The first stage in this validation was to compare the response of the simulated tractor to that of the experimental tractor. By looking at the steady-state gains of the tractor, adjustments were made to the model to more closely match the experimental results. These adjustments included suspension and steering compliances, as well as auxiliary roll moment modifications. Once the validation of the truck tractor was completed for the current configuration, the existing 53-foot box trailer model was added to the vehicle model. The next stage in experimental validation for the current tractor-trailer model was to incorporate suspension compliances and modify the auxiliary roll stiffness to more closely model the experimental response of the vehicle. The final validation stage was to implement some minor modifications to the existing RSC model.

This study was performed to showcase the possible applications of the Hardware-in-the-loop (HIL) simulation environment developed by the National Highway Traffic Safety Administration (NHTSA), to test heavy truck crash avoidance safety systems. In this study, the HIL simulation environment was used to recreate a simulation of an actual accident scenario involving a single tractor semi-trailer combination. The scenario was then simulated with and without an antilock brake system (ABS) and electronic stability control (ESC) system to investigate the crash avoidance potential afforded by the tractor equipped with the safety systems. The crash scenario was interpreted as a path-following problem, and three possible driver intended paths were developed from the accident scene data.

Oblique crashes to the vehicle front corner may not be characteristic of either frontal or side impacts. This research evaluated occupant response in oblique crashes for a driver, rear adult passenger, and a rear child passenger. Occupant responses and injury potential were evaluated for seating positions as either a far-or near-side occupant. Two crash tests were conducted with a subcompact car. The vehicle’s longitudinal axis was oriented 45 degrees to the direction of travel on a moving platform and pulled into a wall at 56 km/h. Dummies utilized for the seating positions were an adult dummy (50th-percentile-HIII and THOR-Alpha) for the front-left (driver) position, 5th-percentile-female-HIII for the right-rear position, and a 3-year-old HIII for the left-rear position.

The evaluation and mitigation of injury in the automotive crash environment is often achieved by monitoring and limiting the magnitude of forces and/or moments being applied to or transmitted through dummy structures representing particular portions of the human anatomy. Examples of body areas where this is the practice are the neck, the thoracic and lumbar spine, the pelvis, as well as the upper and lower extremities. Implicit within this process is the assumption that the observed forces are directly proportional to local failure metrics such as stress and/or strain. However, a variety of experimental efforts have demonstrated that many of these anatomical structures exhibit, to various degrees, viscoelastic behavior and time or rate dependent failure properties. This work develops a methodology that generalizes the results of various experimental observations.

For years, reducing the number of traffic-related fatalities and injuries has been a major problem throughout the world. Today, it has gained much more momentum in view of rapidly increasing SUV, van, and light-truck populations relative to the number of passenger cars, and due to significant improvements in technologies that facilitate a better understanding of the interaction dynamics among widely differing size vehicles. Unless disparities in crashworthiness among vehicles of different masses, sizes, and structural characteristics in mixed crash environments are successfully taken into account, the challenge toward improved vehicle safety will continue. This two-part compendium provides the most comprehensive information available on the entire spectrum of vehicle crash compatibility. The first part presents oral comments captured from the 2003 SAE World Congress panel discussion on compatibility.

This book contains 28 landmark papers, providing a comprehensive look at event data recorder (EDR) technology for cars, light trucks, and heavy vehicles. By collecting EDR data, vehicle safety trends can be established, providing car companies, researchers, and regulators with science-based methods to better understand vehicle crashes. In addition to classic and cutting-edge papers, the book features insightful materials on the new National Highway Traffic Safety Administration (NHTSA) Final Rule on Event Data Recorders (49 CFR, Part 563), including the rule itself, a summary, and the response to petitions for reconsideration.