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A study of injury patterns of older children (aged 6-12 years) indicates that they may deserve more attention from automotive safety researchers. Although older children represent 43.1% of child occupants involved in accidents taken from the National Accident Sampling System (NASS) database, they receive 55.4% of the injuries suffered by children. A lower restraint usage rate (56.2% compared to 63.4% for younger children) partly accounts for this disproportionate amount of injury. However, when restrained, fewer older children remain uninjured compared to younger children (62.8% vs. 70.8%). The number of older children receiving injuries decreases with restraint use (63.6% injured for unrestrained vs. 37.5% injured for restrained). When comparing injuries to restrained and unrestrained older children, the injuries are generally the same severities, but restraints lead to higher proportions of pelvis/abdomen injuries while reducing the occurrence of whole body injuries.

A proposed modification to the Hybrid III 50th percentile male dummy upper femur appears to reduce the chest response problems resulting from femur-pelvis interaction in test exposures more severe than Standard No. 208 testing. When compared to overall repeatability of tests, the modification did not change other dummy response measurements appreciably. The femur-pelvis interaction problem, referred to as “hip lock”, was thought to occur in certain vehicles when the femurs of a passenger side dummy impacting only an air bag bottomed out against the pelvis structure. If metal-to-metal contact occurred, excessive load could be transferred to the chest, leading to elevated chest responses. The most pertinent signs of hip lock occurring appear to be a large, sharply pointed z chest acceleration, and a distinct positive component of the lumbar spine z force following the main negative component.

Locations of key body segments of Hybrid III dummies used in FMVSS 208 compliance tests and NCAP tests were measured and subjected to statistical analysis. Mean clearance dimensions and their standard deviations for selected body segments of driver and passenger occupants with respect to selected vehicle surfaces were determined for several classes of vehicles. These occupant locations were then investigated for correlation with impact responses measured in crash tests and by using a three dimensional human-dummy mathematical model in comparable settings. Based on these data, the importance of some of the clearance dimensions between the dummy and the vehicle surfaces was determined. The study also compares observed Hybrid III dummy positions within selected vehicles with real world occupant positions reported in published literature.

A study of the National Accident Sampling System (NASS) found an increase in upper extremity injuries when drivers were restrained by a seat belt and air bag as opposed to a seat belt alone. These injuries were attributed to forces from the air bag deploying or the air bag projecting the arm into vehicle components or the upper body of the driver. Two evaluation methods were used to assess the extent of injury and aggressiveness of different driver side air bags. The RAID, developed by Conrad Technology, and the Hybrid III instrumented arm, tested at the Vehicle Research and Test Center, were used in static testing to evaluate the effect of air bags on the arm. The positions of the RAID and the Hybrid III arm simulated the arm in four different turning positions with the forearm across the center of the wheel. Both devices recorded arm moments and accelerations. Film analysis determined the cause of the peak resultant moment for each bag in the four configurations.

Assessment of potential forearm fracture due to deployment of driver air bags is examined through a series of static air bag deployments with a specially instrumented Hybrid III dummy. The objective of the study was to determine the feasibility of measuring accelerations and bending moments on the Hybrid III dummy forearm as a potential injury index for arm fracture. Study of the National Accident Sampling System data has shown that in isolated circumstances, deployment of an air bag while the driver is making a turn can lead to fractures of the lower arm. To examine this phenomenon, the Hybrid III dummy was instrumented with accelerometers and strain gages to allow measurement of the accelerations and moments on the right arm. The arm was oriented over the steering wheel towards the eleven o'clock position during deployment of the air bag. Accelerations were measured on the arm at the wrist, elbow, and shoulder. Moments in two axes were measured at two locations below the elbow.

Parallel and coordinated accident studies were conducted in the United States and in the Federal Republic of Germany to determine the extent, the level, and the comparability of neck injuries in automotive accidents as reported in the National Crash Severity Study (NCSS), and the Association of German Automobile Insurers (HUK-Verband) files. To determine the comparability of the two data sets, three primary evaluation criteria were used: 1) the distribution of overall injuries by AIS level by various occupant parameters, 2) the risk of occupant AIS injury vs. delta V, and 3) the distribution of neck injuries by AIS for restrained vs unrestrained occupants. Frequencies and severities of neck injuries in car accidents were compared in parallel layouts between the two data sets in frontal, side and rear impact modes. In further breakdown the frontal impact file was separated into driver/passenger and male/female categories.

The sensitivity of response of crash victim simulation was investigated using a two-dimensional, mathematical eight-mass model. The model was exercised in the forward collision mode in a three-point restraint system using a trapezoidal forcing function. Mass and inertia parameters of the occupant simulation, its setup, and the restraint and environment systems were evaluated individually and as groups, in terms of their effects on the occupant's head and chest acceleration. The study also investigates and rates the effects of shape and time duration of the forcing function upon the response of the occupant.

This paper addresses the kinematics of occupants of light motor vehicles that are involved in frontal collisions. Injury to occupants of these vehicles constitute a majority of the harm incurred in all of the traffic accidents. Host injury is caused by the relatively high velocity collisions of occupants into vehicle interior components. A two dimensional (2-D) MVMA dynamic occupant simulation was used to facilitate the understanding of occupant kinematics in frontal collisions in general and to determine the spectra of occupant impact velocities into vehicle components for a range of crash speeds in particular. Real world accident data and laboratory crash tests were used to provide inputs and boundaries for the MVMA 2-D model. The accident data provided guidelines as to which occupant-to-vehicle impact modes produce the most harm and therefore should be addressed.

A three-part program was undertaken to establish an appropriate means of evaluating child restraints in automobile crashes. A standard seat was designed to provide a reproducible test base on which to evaluate child restraint systems in dynamic testing. Developmental and evaluation data are presented, including child restraint performance tests. Results showed the standard seat to be a durable, repeatable, and economical test platform which provides a realistic base for evaluation of child restraint systems. Commercially available three- and six-year-old child dummies were evaluated for their anthropometric measurements and dynamic response characteristics in pendulum impact tests and simulated crashes in representative automobile-child seat restraint environments. Simulated crashes included 20 and 30 mph frontal and 20 mph side impacts on automobile and specially designed bench seats. Two types of child seats, the G. M.

A solid state, low power, self-contained digital crash recorder was developed and installed in the Part 572 crash test dummy for capturing and storing the crash severity-time event. The crash recorder is capable of recording upon internal triggering command the dummy's response in 10 separate data channels. The recorder's performance was evaluated in laboratory and vehicle tests consisting of simulated and real rigid barrier collisions in the forward impact mode and moving barrier collisions in side impacts. The recorder was found to be suitable for capturing and storing high quality crash data compatible with currently used hardwire data acquisition techniques.

This two part study investigates differences in thorax deflections between volunteers and dummies when they are dynamically loaded by diagonal shoulder belts and it shows how internal measurements at the Hybrid III dummy's sternum relate to external compressions at various points of the rib cage. Test results reveal that the thorax of the Hybrid III dummy, when loaded by a diagonal belt, is somewhat stiffer than that of volunteers for both tensed and relaxed conditions. The thorax of volunteers under dynamic belt loading deflects underneath the belt in an action similar to that of a flat rigid plate being pushed into the thorax with increasing deflection towards the lower part of the ribcage, while the dummy's deflected profile assumes a parabolic curvature.

In 1983, the National Highway Traffic Safety Administration (NHTSA) initiated two air hag vehicle fleet programs. The objective was to demonstrate that both original equipment and retrofit air bag systems operate in vehicles as intended. As of July 1, 1987, the two fleets together have accumulated over 200 million miles. Data are presented for 112 crashes involving air bag deployment in these government sponsored fleet vehicles in service between 1984 and July 1, 1987. Of the 112 drivers involved in the crashes, 103 sustained either no injury or only minor (AIS 1)[1]1 injuries. Of the nine remaining cases, six were AIS 2 and three AIS 3. To date, the limited data indicate that the air bag deployed as expected in all frontal crashes severe enough to require occupant restraint beyond that provided by the vehicle interior. Additionally, in collisions in which the air bag did not deploy, the crashes were of such low severity that no actuation was expected and none took place.

Since 2000, over 200 rear seat occupants have become entangled in the seatbelt when they inadvertently switched it from emergency locking mode (ELR) to automatic locking mode (ALR). Since a method is needed to lock the seatbelt when installing child restraint systems (CRS), the National Highway Traffic Safety Administration (NHTSA) commissioned tool, inc. to develop prototype devices that could reduce the risk of seatbelt entanglement resulting from the lockability requirement. A field analysis of entanglement incidents was first conducted to inform countermeasure design. Prototype devices were developed and evaluated through testing with volunteer subjects in comparison to standard seatbelt systems by assessing how different designs would be used to install CRS, the quality of the resulting installations, how users would disentangle a trapped child surrogate, as well as to identify volunteer experience when using the belts themselves.

Pregnant occupants pose a particular challenge to safety engineers because of their different anthropometry and the additional “occupant within the occupant.” A detailed study of the anthropometry and seated posture of twentytwo pregnant drivers over the course of their pregnancies was conducted. Subjects were tested in an adjustable seating buck that could be configured to different vehicle package geometries with varying belt anchorage locations. Each subject was tested four times over the course of her pregnancy to examine changes in seat positioning, seated anthropometry, and positioning of the lap and shoulder belts with gestational age. Data collected include preferred seating positions of pregnant drivers, proximity of the pregnant occupant to the steering wheel and airbag module, contours of the subjects’ torsos and abdomens relative to seat-belt centerline contours, and subject perceptions of their seated posture and proximity to vehicle components.

This study documented the position and orientation of child restraint systems (CRS) installed in the second rows of vehicles, creating a database of 486 installations. Thirty-one different CRS were evaluated, selected to provide a range of manufacturers, sizes, types, and weight limits. Eleven CRS were rear-facing only, fourteen were convertibles, five were combination restraints, and one was a booster. Ten top-selling vehicles were selected to provide a range of manufacturers and body styles: four sedans, four SUVS, one minivan, and one wagon. CRS were marked with three reference points on each moving component. The contours and landmarks of each CRS were first measured in the laboratory. Vehicle interior contours, belt anchors, and LATCH anchors were measured using a similar process. Then each CRS was installed in a vehicle using LATCH according to manufacturers' directions, and the reference points of each CRS component were measured to document the installed orientation.

A new prototype pregnant abdomen for the Hybrid III small-female ATD is being developed and has been evaluated in a series of component and whole-dummy tests. The new abdomen uses a fluid-filled silicone-rubber bladder to represent the human uterus at 30-weeks gestation, and incorporates anthropometry based on measurements of pregnant women in an automotive driving posture. The response of the new pregnant abdomen to rigid-bar, belt, and close-proximity airbag loading closely matches the human cadaver response, which is thought to be representative to the response of the pregnant abdomen. In the current prototype, known as MAMA-2B (Maternal Anthropomorphic Measurement Apparatus, version 2B), the risk of adverse fetal outcome is determined by measuring the peak anterior pressure within the fluid-filled bladder.

A combination of finite element modeling and sled test reconstruction of real-world infant head injury scenarios has been used to investigate infant head impact response and tolerance to skull fracture. Studying the role of cranial sutures on infant skull response was of particular interest. The specific injury scenarios selected for reconstruction involved infants in rear-facing child restraint systems (CRS) who sustained skull fractures and brain injuries from deploying passenger-side frontal airbags. Approximations of the loading conditions for three injury cases, as well as estimates of loading conditions not expected to result in head injury, were produced in the laboratory. A finite element model (FEM) of a six-month-old infant head was developed using available material properties and humanlike geometry. The infant head FEM was used to simulate different injury and no-injury loading conditions based on CRS response data from the reconstruction tests.

This paper describes results from a survey of older children with respect to vehicle and booster restraints. The work first consisted of a rudimentary anthropometry study of 155 volunteers aged between 7 and 12 years. The data were compared to an extensive child anthropometry study conducted by the University of Michigan in 1975. Height and sitting height data matched well, while children in the current study appeared heavier. In the restraint fit survey, each child sat in the rear seat alone and in three belt-positioning booster seats (Volvo, Kangaroo, Century CR-3) in three vehicles (Ford Taurus, Pontiac Sunbird, Dodge Caravan). Booster seats greatly improved belt fit over the rear seat alone. The majority of children in this study had better belt fit with the boosters than with the rear seat alone, regardless of size. However, children who could fit well in the boosters and had good or fair belt fits were generally 36 kg or less.

A detailed understanding of the size, shape, and postures of children is required to design effective restraint systems for protecting children in motor vehicle crashes. Compiled and edited by experts in the fields of anthropometry, ergonomics, and child restraint, this book includes 14 important papers which provide a comprehensive overview of the methods for collecting, analyzing, and applying child anthropometry data for crash safety purposes. A detailed understanding of the size, shape, and postures of children is required to design effective restraint systems for protecting children in motor vehicle crashes. Compiled and edited by experts in the fields of anthropometry, ergonomics, and child restraint, this book includes 14 important papers which provide a comprehensive overview of the methods for collecting, analyzing, and applying child anthropometry data for crash safety purposes.

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.