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This study compares statistical models for frontal crash injuries based on delta-v data reported by the vehicle event data recorder (EDR) with injury probability models based on delta-v reconstructed by Crash Investigation Sampling System (CISS) investigators. Injury probabilities and their follow-on use in advanced automatic crash notification (AACN) systems have traditionally been based on delta-v obtained through accident reconstruction of field crashes in the National Automotive Sampling System Crash Data System (NASS-CDS) database. Field delta-v from EDRs in the CISS database is an alternative source of information for crash injury probability modeling. In this study, frontal impact injury risk probabilities computed from EDR and reconstructed delta-v were compared. All data came from the years 2017–2021 of the CISS database, which contains EDR downloads and also reconstructed delta-v using crush measurements and NHTSA’s WinSmash software.

This article compares the results of automotive accident reconstructions to event data recorder (EDR) data from vehicles involved in rear-end collisions. Accident reconstructions in the Crash Investigation Sampling System (CISS) database calculate crash severity expressed as the impact-related change in velocity (delta-V) experienced by a vehicle. The accuracy of the CISS-reconstructed delta-V in rear impacts was assessed by comparison to the delta-V recorded during the crash by the EDR on board the rear-ended vehicles. The CISS database was searched for single rear impact cases with a CISS-reconstructed delta-V as well as an EDR download. A total of 256 cases met these criteria. On average, the CISS-reconstructed delta-V was 4.0% lower than the delta-V recorded by the EDR. The accuracy of the CISS reconstructions varied with crash configuration, vehicle type, collision partner, and crash severity.

This paper investigates the role that load-limiters play with respect to the performance of occupant protection systems, with focus on performance in frontal crashes. Modern occupant protection systems consist of not just the seat belt, but also airbags, interior vehicle surfaces and vehicle structure. Modern seat belts very often incorporate load-limiters as well as pretensioners. Published research has established that load-limiters and pretensioners increase the effectiveness of occupant protection systems. Some have argued that load-limiters with higher deployment thresholds are always better than load-limiters with lower deployment thresholds. Through testing, modeling and analysis, we have investigated this hypothesis, and in this paper we present test and modeling data as well as a discussion to this data and engineering mechanics to explain why this hypothesis is incorrect.

The purpose of this study was to determine if quasi-static (QS) bumper force-deformation (F-D) data could be used in a low-speed bumper-to-bumper simulation model (1) in order to reconstruct low-speed crashes. In the simulation model, the bumpers that make contact in a crash are treated as a system. A bumper system is defined as the two bumpers that interact in a crash positioned in their orientation at the time of the crash. A device was built that quasi-statically crushes the bumpers of a bumper system into each other and measures the compression force and the deformation of the bumper system. Three bumper systems were evaluated. Two QS F-D measurements were performed for each bumper system in order to demonstrate the repeatability of the QS F-D measurement. These measurements had a compression phase and a rebound phase. A series of crash tests were performed using each bumper system.

Calculating head accelerations and neck loading is essential for understanding and predicting head and neck injury. Most of the desired information cannot be directly measured in experiments with human volunteers. Achieving accurate results after applying the necessary transformations from remote measurements is difficult, particularly in the case of a head impact. The objective of this study was to develop a methodology for accurately calculating the accelerations at the center of gravity of the head and the loads and moments at the occipital condyles. To validate this methodology in a challenging test condition, twenty (20) human volunteers and a Hybrid III dummy were subjected to forehead impacts from a soccer ball traveling horizontally at speeds up to 11.5 m/s. The human subjects and the Hybrid III were instrumented with linear accelerometers and an angular rate sensor inside the mouth.

Previous literature has shown that serious neck injury can occur during rollover events, even for restrained occupants, when the occupant's head contacts the vehicle interior during a roof-to-ground impact or contacts the ground directly through an adjacent window opening. Confusion about the mechanism of these injuries can result when the event is viewed from an accelerated reference frame such as an onboard camera. Researchers generally agree that the neck is stressed as a result of relative motion between head and torso but disagree as to the origin of the neck loading. This paper reviews the principles underlying the analysis of rollover impacts to establish a physical basis for understanding the source of disagreement and demonstrates the usefulness of physical testing to illustrate occupant impact dynamics. A series of rollover impacts has been performed using the Controlled Rollover Impact System (CRIS) with both production vehicles and vehicles with modified roof structures.

The purpose of this study is to determine the loads in the long bones of the lower extremities during vehicle pedestrian impact tests, and to correlate load data with observed kinematics in an effort to understand how stature and vehicle shape influence pedestrian response. In tests with a large sedan and a small multi-purpose vehicle (MPV), four postmortem human surrogates (PMHS) in mid-stance gait were struck laterally at 40 km/h. Prior to the tests, each PMHS was instrumented with four uniaxial strain gages around the mid-shaft cross section of the struck-side (right) tibia and the femora bilaterally. After the tests, the non-fractured bones were harvested and subjected to three-point bending experiments. The effective elastic moduli were determined by relating the applied bending loads with the measured strains using strain gage locations, detailed bone geometry, and elastic beam theory.

Recently, it has been demonstrated experimentally that the so-called “whiplash” response during low velocity rear-end collisions may produce a spontaneously resolving strain injury to muscles of the neck, but that injury to other spinal elements is biomechanically improbable. This paper reviews the results of these studies as a means of addressing the longstanding controversy which surrounds “whiplash” and the claims that the “whiplash” response produces more extensive injuries. It is concluded that there are no objective, experimentally-based scientific data to support the concept that the low-velocity “whiplash” response is capable of producing any injuries beyond those to the cervical musculature.