Occupant Protection in Far Side Crashes (original) (raw)
Side Impact Injury Risk for Belted Far Side Passenger Vehicle Occupants
SAE Technical Paper Series, 2005
In a side impact, the occupants on both the struck, or near side, of the vehicle and the occupants on the opposite, or far side, of the vehicle are at risk of injury. Since model year 1997, all passenger cars in the U.S. have been required to comply with FMVSS No. 214, a safety standard that mandates a minimum level of side crash protection for near side occupants. No such federal safety standard exists for far side occupants. The mechanism of far side injury is believed to be quite different than the injury mechanism for near side injury. Far side impact protection may require the development of different countermeasures than those which are effective for near side impact protection. This paper evaluates the risk of side crash injury for far side occupants as a basis for developing far side impact injury countermeasures. Based on the analysis of NASS/CDS 1993-2002, this study examines the injury outcome of over 4500 car, light truck, and van occupants subjected to far side impact. The analysis was restricted to 3-point belted occupants. The paper evaluates the risk of far side impact injury as a function of struck body type, collision partner, delta-V, crash direction (PDOF), occupant compartment intrusion, and injury contact source. Injury risk is evaluated using the maximum injury severity for each occupant, by injury severity for each body region, and by Harm, a social cost measure.
Side Impact Crashes and Countermeasures
2005
Side impact collisions are a major road safety problem in most western countries, accounting for up to 35% of all severe road trauma and the problem is not currently addressed effectively. While crash severities tend to be relatively low, the injuries sustained to occupants seated in the struck (near side) and non-struck or far side, tend to be severe and life threatening. The most common side impacts occur at intersections (car-car crashes) and pole or tree collisions (single-vehicles). Examples of in-depth examination of side impacts show severe damage to the car and the occupants from these crashes. The paper offers a range of countermeasures to reduce these impacts or mitigate the severity of occupant injuries.
Accident Analysis & Prevention, 2005
The goal of this study was to identify variables related to vehicle design which are associated with pelvic and thoracic accelerations as measured by the driver's (near side) crash dummy during new car assessment program (NCAP) testing of motor vehicles. Vehicle specific parameters were analyzed using NCAP side impact test results. Data from national automotive sampling system, crashworthiness data system (NASS-CDS) and crash injury research and engineering network (CIREN) (both National Highway Traffic Safety Administration (NHTSA) injury databases) were assessed to confirm NCAP test observations. In addition, door armrest stiffness measurements were performed using a mechanical tester on a sample of 40 vehicles. NCAP data showed that of 10 variables tested using multiple linear regression, vehicle weight and door crush correlated with pelvic acceleration of the driver's crash dummy (overall, r 2 = 0.58, p = 0.002, n = 165). For thoracic trauma index (TTI) vehicle weight and peak door velocity correlated, significantly (overall, r 2 = 0.41, p = 0.03, n = 165). Mean TTI was 63.7 g with no side airbag (n = 108) and 55.6 g with a thoracic side airbag (n = 54), p = 0.01. The mean vehicle weight and door crush between airbag and no airbag groups were not significantly different. NASS-CDS data demonstrated a direct relationship between increased door crush and increased abbreviated injury score (AIS). CIREN data showed that occupants who sustained pelvic injuries had a median AIS of 3 with 24.9 cm of door crush, with abdominal injuries, a median AIS of 3 and 30 cm of crush, and with thoracic injuries, a median AIS of 4 and 34 cm of door crush. In addition, the frequency of bilateral pelvic injuries was significantly higher for subjects in CIREN crashes who were in a vehicle with a center console, but only if door intrusion was greater than 15 cm. This information may be useful in design of vehicles with greater protection in side impact crashes.
A Safety Rating for Farside Crashes
A research team from Australia, Europe and the United States has conducted the research needed to provide a technology base for far-side crash protection. To date the findings are as follows: (1) in the USA and Australia there are large opportunities in far-side impact injury reduction, especially if safety features could mitigate injuries in both far-side planar impacts and rollovers, (2) a modified MADYMO human facet model was validated for use in evaluating far-side countermeasures, (3) either the THOR-NT or the WorldSID dummy would be satisfactory test devices for assessing far-side protection with minor modifications such as changing in the location of the chest instrumentation and (4) injury criteria and risk functions for use with WorldSID in far-side crashes have been documented. There is now a sufficient technology base so that far- side protection can be evaluated and rated by consumer information tests.
Biomechanics of side impact: Injury criteria, aging occupants, and airbag technology
Journal of Biomechanics, 2007
This paper presents a survey of side impact trauma-related biomedical investigations with specific reference to certain aspects of epidemiology relating to the growing elderly population, improvements in technology such as side airbags geared toward occupant safety, and development of injury criteria. The first part is devoted to the involvement of the elderly by identifying variables contributing to injury including impact severity, human factors, and national and international field data. This is followed by a survey of various experimental models used in the development of injury criteria and tolerance limits. The effects of fragility of the elderly coupled with physiological changes (e.g., visual, musculoskeletal) that may lead to an abnormal seating position (termed out-of-position) especially for the driving population are discussed. Fundamental biomechanical parameters such as thoracic, abdominal and pelvic forces; upper and lower spinal and sacrum accelerations; and upper, middle and lower chest deflections under various initial impacting conditions are evaluated. Secondary variables such as the thoracic trauma index and pelvic acceleration (currently adopted in the United States Federal Motor Vehicle Safety Standards), peak chest deflection, and viscous criteria are also included in the survey. The importance of performing research studies with specific focus on out-of-position scenarios of the elderly and using the most commonly available torso side airbag as the initial contacting condition in lateral impacts for occupant injury assessment is emphasized.
The technology base for far side occupant protection
2008
A technical team from Australia, Europe and the United States has been assembled to plan and conduct the research needed to provide a technology base for far-side crash protection. To date the findings are as follows: (1) in the USA and Australia there are large opportunities for far-side injury reduction, especially if safety features could mitigate injuries in both far-side planar impacts and far-side rollovers, (2) the IIHS test barrier offers considerable promise as a suitable test device to induce the damage that is representative of farside crashes that produce injury, but the test speed should be higher for far-side crashes than for near-side crashes, (3) a modified MADYMO human facet model was validated for use in evaluating far-side countermeasures, (4) either the THOR-NT or the WorldSID dummy would be a satisfactory test device for assessing far-side protection, but would require minor modifications such as changing in the location of the chest instrumentation and (5) inju...
Analysis of occupant kinematics and dynamics in nearside oblique impacts
Traffic Injury Prevention, 2016
The objective of the paper is to analyze the kinematics and dynamics of restrained Post Mortem Human Surrogates (PMHS) exposed to a nearside oblique impact and the injuries that were found after the tests. Methods Three male PMHS of similar age (64 ± 4 years) and anthropometry (weight: 61 ± 9.6 kg; stature: 172 ± 2.7 cm) were exposed to a 30 deg nearside oblique impact at 34 km/h. The test fixture approximated the seating position of a front seat occupant. A rigid seat was designed to match the pelvic displacement in a vehicle seat. Surrogates were restrained by a three-point seat belt consisting of a 2 kN pretensioning (PT), 4.5 kN force-limiting shoulder belt and a 3.5 kN PT lap belt. The shoulder belt PT was not fired in one of the tests. Trajectories of the head, shoulder and hip joint (bilaterally) were recorded at 1,000 Hz by a three-dimensional (3D) motion capture system. The 3D acceleration and angular rate of the head, T1 and pelvis, and the 3D acceleration of selected spinal locations were measured at 10,000 Hz. Seat belt load cells measured the belt tension at four locations. PMHS donation and handling were performed with the approval of the relevant Regional Ethics Review Board. Results The activation of the shoulder PT reduced substantially the peak forward excursion of the head but did not influence the lateral displacement of the head CG. In all the three subjects, the lateral excursion of the head CG (291.1 mm, 290 mm, 292.1 mm) was greater than the forward displacement (271.4 mm, 216.7 mm, 171.5 mm). The hip joint excursion of the PMHS that was not exposed to the shoulder PT seat belt was twice the magnitude observed for the other two subjects. The three PMHS sustained clavicle fractures on the shoulder loaded by the seatbelt and two of them were diagnosed atlantoaxial subluxation in the radiologist examination. Avulsion fractures of the right lamina of T1, T2, T3 and T4 were found when the PT was not used. The three PMHS received multiple fractures spread over both aspects of the rib cage and involving the posterior aspect of it. Conclusion In this study of nearside oblique impact loading, the PMHS exhibited kinematics characterized by reduced torso pitching and increased lateral head excursion as compared to previous frontal impact results. These kinematics resulted into potential cervical and thoracic spinal injuries and into complete, displaced fractures of the lateral and posterior aspects of the rib cage. While this is a limited number of subjects, it shows the necessity of further understanding of the kinematics of occupants exposed to this loading mode. * The pelvic accelerometer block hit the seat in the first test due to the oblique motion of the pelvis. No instrumentation was added to the second test. In the third test, a new tridimensional acceleration block was added to the pelvis, but it was attached laterally to the right iliac crest to avoid interference with the seat hardware.
Optimal Side Impact Protection
… Conference (16-17 …, 1998
Previous research has shown that side impact crashes account for a substantial proportion of injuries and Harm to Australian passenger car occupants. Fildes, Lane, Lenard and Vulcan (1994) reported that 25% of serious casualties and 28% of fatalities to vehicle occupants ...
2017
for his continuous support and patience. His guidance helped me throughout my master's degree program. It has been a privilege to perform my duties as his Graduate Teaching Assistant, and this thesis would not have been successful without his valuable guidance. I also thank my esteemed committee members, Dr. Krishna Krishnan and Dr. Yimesker Yihun, for their helpful comments and suggestions. I would like to express my profound gratitude to my parents and to my siblings for their endless love and encouragement. My family is my strength and everything. I also thank my friends and the faculty of the Department of Mechanical Engineering at Wichita State University for their constant support.
SAE Technical Paper Series
The UK in-depth data, describing the causation of injuries to casualties in side impacts, was examined for crashes occurring between 1992 and 1998. Slightly more casualties died in side impacts than in frontal crashes, and one third were seated on the side away from the collision. The collision severity was compared with the European and US legal test procedures and most MAIS 3+ survivors were observed to be in crashes above the severity of the test. The mean delta-V for the fatal group was 48 km/h compared with typically 25 km/h in the test. The most commonly injured body regions of both survivors and fatalities were the head, thorax and lower extremity. The lower extremity was the most frequent site of AIS 2+ injuries of survivors and fractures to the femur and tibia were highlighted, these injuries are not assessed by existing dummies. small study of 39 car-to-car side impact collisions. They reported