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Head injuries are the most common injuries sustained by children in motor vehicle crashes regardless of age, restraint and crash direction. Previous research identified the front seat back as relevant contact point associated with head injuries sustained by restrained rear seated child occupants. The objective of this study was to conduct a test series of headform impacts to seat backs to evaluate the energy management characteristics of relevant contact points for pediatric head injury. A total of eight seats were tested: two each of 2007 Ford Focus, Toyota Corolla, 2006 Volvo S40, and 2008 Volkswagen Golf. Five to six contact points were chosen for each unique seat model guided by contact locations determined from real world crashes. Each vehicle seat was rigidly mounted in the center track position with the seatback angle adjusted to 70 degrees above the horizontal.

Recently there has been a greater awareness of the increased risk of certain injuries associated with air bag deployment, especially the risks to small occupants, often women. These injuries include serious eye and upper extremity injuries and even fatalities. This study investigates the interaction of a deploying air bag with cadaveric upper extremities in a typical driving posture; testing concentrates on female occupants. The goals of this investigation are to determine the risk of upper extremity injury caused by primary contact with a deploying air bag and to elucidate the mechanisms of these upper extremity injuries. Five air bags were used that are representative of a wide range of air bag ‘aggressivities’ in the current automobile fleet. This air bag ‘aggressivity’ was quantified using the response of a dummy forearm under air bag deployment.

This paper discusses the consumer and news media perceptions about air bags that had to be taken into account by the National Highway Traffic Safety Administration in making rulemaking decisions in 1997. Addressing these perceptions was a major concern as the agency made preparations to allow identifiable groups of people at risk from an air bag deployments to have on-off switches installed in their vehicles.

The protection of a vehicle occupant in a frontal crash is a combination of vehicle front structural design and occupant restraint design. Once chosen and manufactured, these design features must interact with a wide variety of structural characteristics in potential crash partners. If robust, the restraint design will provide a high level of protection for a wide variety of crash conditions. This paper examines how robust a given restraint system is for occupant self-protection and how frontal design can improve the restraint performance of potential crash partners, thus improving their restraint robustness as well. To examine restraint robustness in self protection, the effect of various vehicle deceleration characteristics on occupant injury potential is investigated for a given restraint design. A MADYMO model of a 1996 Taurus interior and its restraint system with a Hybrid III 50th percentile male dummy are simulated and subjected to 650 crash pulses taken during 25 years of U.S.

Since 1994, the New Car Assessment Program (NCAP) of the National Highway Traffic Safety Administration (NHTSA) has compiled upper neck loads for the belt and air bag restrained 50th percentile male Hybrid III dummy. Over five years from 1994 to 1998, in frontal crash tests, NCAP collected upper neck data for 118 passenger cars and seventy-eight light trucks and vans. This paper examines these data and attempts to assess the potential for neck injury based on injury criteria included in FMVSS No. 208 (for the optional sled test). The paper examines the extent of serious neck injury in real world crashes as reported in the National Automotive Sampling System (NASS). The results suggest that serious neck injuries do occur at higher speeds for crashes involving occupants restrained by belts in passenger cars.

Mathematical models in combination with mechanical tests were used to develop a frontal crash sensing system and algorithm. The required sensor closure time for the initiation of driver side airbag deployment was estimated by means of multi body dynamics occupant models. The crash sensing system and algorithm were developed using predictions from a finite element model of the front structure of a passenger vehicle. All models were validated by means of mechanical tests. Generally good agreement was obtained between the predictions from the models and the results from the mechanical tests. In the sensor closure time analysis two occupant sizes were used, the 50%-ile male and the 5%-ile female occupant. Two restraint conditions were evaluated, no belt and a belt system incorporating a pretensioner. A number of crash pulses of various severity were used.

A research program was initiated to evaluate the performance of prototype dual stage passenger air bags in terms of both restraint system performance and deployment aggressivity for different size occupants. Variations in inflator partitions, vent hole diameter sizes, and deployment timing were examined. High speed unbelted sled tests were conducted with both 50th percentile male and 5th percentile female Hybrid III adult dummies at 48 kmph; and belted sled tests were conducted at 56 kmph. Low risk deployment tests with child dummies were conducted to evaluate air bag aggressivity. Overall, it was concluded that the dual stage air bag systems under evaluation had improved performance over the baseline single stage systems in terms of providing high speed protection while reducing aggressivity to out-of-position occupants; however, some dual stage systems may require additional occupant detection methodologies to suppress or control inflation.

The performance of air bags, as an occupant protection system, is of high interest to the National Highway Traffic Safety Administration (NHTSA or Agency). Since 1972, the NHTSA has operated a Special Crash Investigations (SCI) program which provides in-depth crash investigation data on new and rapidly changing occupant protection technologies in real-world crashes. The Agency uses these in-depth data to evaluate vehicle safety systems and form a basis for rulemaking actions. The data are also used by the automotive industry and other organizations to evaluate the performance of motor vehicle occupant protection systems such as air bags. This paper presents information from NHTSA's SCI program concerning crash investigations on air-bag-equipped vehicles. The paper focus is on data collection and some general findings in air bag crash investigations including: air-bag-related fatal and life-threatening injuries; side air bags; redesigned air bags and advanced air bags.

Several thoracic and head protection side impact air bag systems (SAB) are emerging in the U.S. market and are projected to become prevalent in the fleet. These systems appear to offer superior protection in side crashes. However, concerns have been raised as to their potential for causing injury to out-of-position (OOP) occupants. This paper describes the National Highway Traffic Safety Administration (NHTSA) program for evaluation of the SAB systems for OOP occupants and provides a status report on the current research. The industry's Side Airbag Out-of- Position Injury Technical Working Group (TWG) recommended procedures for 3-year-old and 6-year-old occupants are evaluated. Additional test procedures are described to augment the TWG procedures for these occupants and 12-month- old infants.

Real-world crash investigations have suggested that lower limb injury risk is increased with the occurrence of toepan intrusion in a frontal collision. In order to more closely evaluate the effects of different modes of toepan intrusion, a rotational and translational intrusion device was built for the test sled at the University of Virginia. Sled tests were performed at a velocity of 56 km/h with a belted Hybrid III occupant and a simulated knee bolster and steering wheel air bag. Lower limb injury risk measures were obtained with Hybrid III and Thor Lx dummy lower extremities. Dummy response variables of interest included tibia axial and shear loads, tibia bending moments, ankle rotations and foot and tibia accelerations. The tests were conducted with no intrusion and with a translational intrusion with a peak deceleration of approximately 175 g's with 14 cm of translation.

NHTSA conducted seventy-six side impact FMVSS No. 214 compliance tests from 1994 through 1997. The compliance tests are nearly right angle side impacts with low longitudinal components of change of velocity (Δv). Frontal air bag deployments were found to have occurred for 34% of the driver bags and 32% of the front passenger bags in these compliance-tested passenger cars. In 1997, NHTSA began testing passenger cars 'in side impact in the New Car Assessment Program (NCAP). The NCAP crash tests are conducted at a higher speed than the compliance tests. The cars in the NCAP side impact tests also had low longitudinal components of Δv. Approximately 40% of the twenty-six passenger cars tested in the 1997 Side Impact NCAP had their frontal air bags deploy. Real world crash data were examined to determine if frontal air bags are deploying in right angle side impacts on the roads of the US.

Injuries to the thorax and abdomen comprise a significant percentage of all occupant injuries in motor vehicle accidents. While the percentage of internal chest injuries is reduced for restrained front-seat occupants in frontal crashes, serious skeletal chest injuries and abdominal injuries can still result from interaction with steering wheels and restraint systems. This paper describes the design and performance of prototype components for the chest, abdomen, spine, and shoulders of the Hybrid III dummy that are under development to improve the capability of the Hybrid III frontal crash dummy with regard to restraint-system interaction and injury-sensing capability.

In the New Car Assessment Program (NCAP), beginning with the model year 1994 vehicles, the National Highway Traffic Safety Administration (NHTSA) developed and adopted a simplified nonnumeric format for presenting the comparative frontal crashworthiness safety information to consumers. This paper presents the basis for the development of this “star rating” system. The injury probability functions which are used for the star rating system are also applied to the results of the recent NCAP real-world correlation studies and a review of these studies is given. The safety performance for restrained occupants as measured in NCAP is dependent on several parameters which include: the design of the restraint system, the maintenance of the integrity of the occupant space, and the energy management performance of the front structure.

Sixty-three simulated frontal impacts using cadaveric specimens were performed to examine and quantify the performance of various contemporary automotive restraint systems. Test specimens were instrumented with accelerometers and chest bands to characterize their mechanical responses during the impact. The resulting thoracic injury severity was determined using detailed autopsy and was classified using the Abbreviated Injury Scale. The ability of various mechanical parameters and combinations of parameters to assess the observed injury severities was examined and resulted in the observation that belt restraint systems generally had higher injury rates than air bag restraint systems for the same level of mechanical responses. To provide better injury evaluations from observed mechanical parameters without prior knowledge of what restraint system was being used, a dichotomous process was developed.

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.

The paper reviews one hundred and three (103) cases of restrained children involved in motor vehicle crashes and admitted to the level I trauma center at Children's National Medical Center (CNMC). Thirty percent (30%) of these cases involved injuries with an Abbreviated InjuryScore (AIS) severity of 3 or greater. All cases are classified first by type of restraint system, i.e. infant seat, convertible seat, booster seat, lap belt, and lap and shoulder belt, and second, by type of injury sustained, i.e. head/face and neck, upper extremity, thorax, pelvic and abdominal, and lower extremity. The links between these classifications are examined to identify particular injury patterns associated with the use of individual restraint systems, e.g. the incidence of pelvic and abdominal injury associated with the use of both lap and lap and shoulder belts. For the severe injury cases the paper further examines the injury mechanisms for the most commonly observed patterns.

The number of passenger vehicles with combined 3-point belt/driver air bag restraint systems is steadily increasing. To investigate the effectiveness of this restraint combination, 48 kph frontal collisions were performed with human cadavers. Each cadaver's thorax was instrumented with a 12-accelerometer array and two chest bands. The results show, that by using a combined standard 3-point belt (6% elongation)/driver air bag, the thoracic injury pattern remained located under the shoulder belt. The same observation was found when belts with 16% elongation were used in combination with the driver air bag. Chest contours derived from the chest bands showed high local compression and deformation of the chest along the shoulder belt path, and suggest the mechanism for the thoracic injuries.

In the United States, air bags will be required in all passenger cars and light trucks under Federal Motor Vehicle Safety Standard (FMVSS) No. 208, Occupant Crash Protection. Even after full implementation of driver and passenger air bags as required by FMVSS No. 208, frontal impacts will still account for up to 8,000 fatalities and 120,000 moderate to critical injuries (i.e., injuries of AIS ≥ 2) [1]. The National Highway Traffic Safety Administration (NHTSA) has an ongoing research program to address these fatalities and injuries and provide a basis for the possible future upgrade of FMVSS No. 208. This effort includes developing supplementary test procedures for the evaluation of occupant injury in higher severity crashes, developing improved injury criteria including criteria for assessing injuries to additional body regions, and evaluating the injuries associated with occupant size [2, 3 and 4].

A study of frontal collisions using the NASS data base showed that there were four times as many arm injuries to belt restrained drivers who had an air bag deploy than for the drivers who were simply belted. By far, the distal forearm/hand was the most commonly injured region. Hard copy review identified two modes of arm injury related to the deploying air bag: 1) The arm is directly contacted by the air bag module and/or flap cover, and 2) The arm is flung away and contacts an interior car surface. Based on the field studies, a mechanical device called the Research Arm Injury Device (RAID) was fabricated to assess the aggressivity of air bags from different manufacturers. Results from static air bag deployment tests with the RAID suggested that the RAID was able to clearly distinguish between the aggressive and non-aggressive air bags. Maximum moments ranging between 100 Nm and 650 Nm, and hand fling velocity ranging between 30 and 120 km/h were measured on the RAID in these tests.

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.