Showing papers by "Jason R. Kerrigan published in 2011"

Human surrogates for injury biomechanics research.

Abstract: This article reviews the attributes of the human surrogates most commonly used in injury biomechanics research. In particular, the merits of human cadavers, human volunteers, animals, dummies, and computational models are assessed relative to their ability to characterize the living human response and injury in an impact environment. Although data obtained from these surrogates have enabled biomechanical engineers and designers to develop effective injury countermeasures for occupants and pedestrians involved in crashes, the magnitude of the traffic safety problem necessitates expanded efforts in research and development. This article makes the case that while there are limitations and challenges associated with any particular surrogate, each provides a critical and necessary component in the continued quest to reduce crash-related injuries and fatalities.

Test system, vehicle and occupant response repeatability evaluation in rollover crash tests: the deceleration rollover sled test

Abstract: The goal of this study was to evaluate the repeatability afforded by a rollover test system in terms of the test conditions, vehicle and occupant response, and vehicle deformations. Eight full-scale rollover tests were performed using three 2002 Ford Explorer vehicles, instrumented with anthropomorphic test devices and arrays of accelerometers and angular velocity sensors, to examine both intra- and inter-vehicle repeatability in five non-destructive low-speed (LS) and three full-thrown high-speed (HS) rollover crash tests using the deceleration rollover sled method. The cart was accelerated to the target velocity (LS: 19.3 km/h, n = 5; HS: 48.3 km/h, n = 3) and then decelerated (soil trip simulation) to initiate vehicle roll. All five LS and the first two HS tests showed a high degree of repeatability (peak lateral acceleration: 5.3 ± 0.2 g LS and 5.5–6.5 g HS; peak roll rate: 134 ± 12 deg/s LS and 237.3–237.4 deg/s HS; peak curb force: 92.4 ± 2.0 kN LS and 92.6–92.9 kN HS; peak dummy head resultant acce...

Comprehensive computational rollover sensitivity study, Part 1: influence of vehicle pre-crash parameters on crash kinematics and roof crush

Abstract: In 2008, fatalities resulting from vehicle rollover events accounted for over one third of all fatalities resulting from motor vehicle crashes. This study describes the initial phase of a detailed computational study aimed at developing causal relationships between crash, occupant, and vehicle parameters and injury outcome using state-of-the-art computational methods. This initial phase examines the sensitivity of vehicle kinematics and structural deformation by isolating the roof-to-ground interaction phase of the rollover event using an LS-DYNA finite element full-vehicle model. Structural deformation is quantified by a measure of the maximum roof intrusion into the occupant space (average = 44 cm, range = 9–66 cm). Roll angle, pitch angle and drop height have a significant effect on structural deformation, while roll rate and yaw angle do not show significant effects. Drop height alone accounts for 70% of the variability in peak roof crush and vertical acceleration, metrics that are related to causal m...

Characterization of the Pediatric Chest and Abdomen Using Three Post-Mortem Human Subjects

Abstract: This paper reports a series of experiments on 6, 7, and 15 year-old pediatric post-mortem human subjects (PMHS) undertaken to guide the scaling of existing adult thoracic response data for application to the child and to assess the validity of a juvenile porcine abdominal model. The pediatric PMHS exhibited abdominal response similar to the swine, including the degree of rate sensitivity. The thoraces of the PMHS were as stiff as, or slightly more stiff than, published adult corridors. An assessment of age-related changes in thoracic stiffness supports the authors' earlier suggestion (2009) that the effective stiffness of the chest increases through the fourth decade of life and then decreases, resulting in stiffness values similar for children and elderly adults.

Planar impacts in rollover crashes: significance, distribution and injury epidemiology.

Abstract: While one third of all fatal motor vehicle crashes involve rollover of the vehicle, a substantially large portion of these rollover crashes involve planar impacts (e.g., frontal, side or rear impact) that influence the crash kinematics and subsequently the injury outcome. The objective of the study was to evaluate the distribution of planar impacts in rollover crashes, and in particular, to describe the differences in the underlying crash kinematics, injury severity and the regional distribution of injuries when compared to the rollover-dominated crashes without significant planar impact (i.e., primary rollovers). Sampled cases (n=6,900) from the U.S. National Automotive Sampling System – Crashworthiness Data System, representing approximately 3.3 million belted drivers involved in a rollover crash in years 1998–2008, were analyzed. Single vehicle rollover crashes with significant planar impact (21% of all rollover crashes) were in general more likely to result in occupant fatality and involved higher incidence of moderate to severe injuries compared to single vehicle primary rollovers (p<0.05). A substantial proportion of the planar impact rollovers ended in single quarter turn crashes (30%), mostly resulting from a frontal impact (59%). While chest was the most frequently injured body region among all rollover victims sustaining severe injuries, severe injuries sustained in primary rollovers were more isolated (single body region) in comparison to the ones sustained in rollovers with planar impacts. The results emphasize the higher risk of rollover victims sustaining an injury and the differences in distribution of injuries sustained when a planar impact is associated with the rollover crash.

Vehicle Greenhouse Shape Analysis for Design of a Parametric Test Buck for Dynamic Rollover Testing

Abstract: The goal of this study was to define a set of vehicle greenhouse geometries that are representative of the current vehicle fleet for use on a parametric rollover test buck Greenhouse geometry data for 60 vehicles were taken from New Car Assessment Program (NCAP) test reports and compiled in a database for analysis The database was then used to determine XYZ coordinates for landmark points that characterized the greenhouse geometries for those 60 vehicles These landmark-based greenhouse representations were then analyzed and grouped into one of three groups using an Optimization technique The mean shape was found for each group, and this was used as a representation of the group These three representative shapes were found to have a maximum variation of 15 degrees in the windshield angle, 120 mm in roof rail height, 119 mm in greenhouse roofline width, and 258 mm in B- to C-pillar length