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Far-side occupants are not addressed in current government regulations around the world even though they account for up to 40% of occupant HARM in side impact crashes. Consequently, there are very few crash tests with far-side dummies available to researchers. Sled tests are frequently used to replicate the dynamic conditions of a full-scale crash test in a controlled setting. However, in far-side crashes the complexity of the occupant kinematics is increased by the longer duration of the motion and by the increased rotation of the vehicle. The successful duplication of occupant motion in these crashes confirms that a sled test is an effective, cost-efficient means of testing and developing far-side occupant restraints or injury countermeasures.

The National Highway Traffic Safety Administration (NHTSA) Special Crash Investigations database contains twelve completed cases of child fatalities in rearward facing child seats caused by deploying air bags. Three of these are now available for examination. An additional two cases were investigated by the William Lehman Injury Research Center at the University of Miami School of Medicine. These five cases are examined to evaluate crash environment, injury mechanisms, and circumstances which caused the child to be in front of the passenger side air bag Four of the cases were crashes with impacts with the side of other cars with crash severities less than 15 mph. The predominate injury mechanism was brain and skull injury from a blow transmitted to the rear of the head through the child seat back. In one case, the force to the head was transmitted downward, directly from air bag contact.

The factors that influence airbag-induced upper-extremity injuries sustained by drivers were investigated in this study. Seven unembalmed human cadavers were used in nineteen direct-forearm-interaction static deployments. A single horizontal-tear-seam airbag module and two different inflators were used. Spacing between the instrumented forearm and the airbag module was varied from 10 cm to direct contact in some tests. Forearm-bone instrumentation included triaxial accelerometry, crack detection gages, and film targets. Internal airbag pressure was also measured. The observed injuries were largely transverse, oblique, and wedge fractures of the ulna or radius, or both, similar to those reported in field investigations. Tears of the elbow joint capsule were also found, both with and without fracture of the forearm.

Four unembalmed human cadavers were used in eight direct-forearm-airbag-interaction static deployments to assess the relative aggressivity of two different airbag modules. Instrumentation of the forearm bones included triaxial accelerometry, crack detection gages, and film targets. The forearm-fracture predictors, peak and average distal forearm speed (PDFS and ADFS), were evaluated and compared to the incidence of transverse, oblique, and wedge fractures of the radius and ulna. Internal-airbag pressure and axial column loads were also measured. The results of this study support the use of PDFS or ADFS for the prediction of airbag-induced upper-extremity fractures. The results also suggest that there is no direct relationship between internal-airbag pressure and forearm fracture. The less-aggressive system (LAS) examined in this study produced half the number of forearm fracture as the more-aggressive system (MAS), yet exhibited a more aggressive internal-pressure performance.

To date, anthropomorphic test devices (ATDs) have not been designed with consideration for human motion in far-side impacts. Previous tests with a cadaver and a BioSID dummy at the Medical College of Wisconsin confirmed that the dummy does not suitably model the human motion. To further evaluate different ATDs in far-side crashes, MAthematical DYnamic MOdeling (MADYMO) was employed. The modeling showed that the motion of a Hybrid III, BioSID, EuroSid1, EuroSID2, or SID2s did not accurately reflect the motion of a human cadaver under the same impact configurations as the cadaver test. The MADYMO human facet model was found to closely reproduce the kinematics of the cadaver test. The effect of varying console designs on occupant kinematics is presented in this paper. The human facet model appears to be a good interim tool for the evaluation of countermeasures in far-side crashes.

This paper creates a worksheet to thoroughly document vehicle damage during an incompatible vehicle-to-vehicle frontal crash. This data form serves as a supplement to the current and already established NASS inspection forms. It will assist biomechanics research by determining the extent by which incompatibility caused or changed occupants' injuries through structural analysis of the vehicles. This study identifies deficiencies in the current NASS inspection system for compatibility, and develops new measurable parameters to document the crash and associate injury to it.

Rollover crashes continue to be a serious and growing vehicle safety problem. Rollovers account for about 9% of passenger car crashes, and 26% of light truck crashes. Belt use in rollover crashes is about 51%, compared with 62% in planar crashes. Overall, 26.4% of the serious and fatal injuries to occupants exposed to crashes are in rollovers. Among this injured population 74.4% are unbelted. In light trucks, rollovers account for 47.4% of the serious or fatal injuries. Unbelted occupants suffer about 87% of the serious injuries and fatalities in light truck rollovers. The use of safety belts offers a dramatic reduction in injury rates for rollover crashes. For belted occupants of pickup trucks and utility vehicles in rollover crashes, the injury rates are about the same as for belted occupants of passenger cars in planar crashes. Improvementsts in safety belts offer large opportunities in safety.

The purpose of this paper is to assess the vehicle environment that a child occupant, between the ages of seven and thirteen years old, is exposed to in a real world crash. The focus of analysis is on those child occupants that are seated at the struck side in a lateral collision. This study was based on data extracted from the National Automotive Sampling System / Crashworthiness Data System (NASS/CDS) between years 1991-2006. Analysis was based upon the evaluation of the projected consequence of injury to the child occupants. The societal costs generated as a result of occupant injuries were quantified. The societal cost, or Harm, acts as a measure of consequence of occupant exposure to the vehicle environment, when involved in a collision. The Harm was determined as a function of ΔV, principal direction of force, vehicle extent of damage, the pattern of damage to the vehicle, and the magnitude of intrusion based on the occupant seating position.

Vehicle stiffness is one of the three major factors in vehicle to vehicle compatibility in a frontal crash; the other two factors are vehicle mass and frontal geometry. Vehicle to vehicle compatibility in turn is an increasingly important topic due to the rapid change in the size and characteristics of the automotive fleet, particularly the increase of the percentage of trucks and SUVs. Due to the non-linear nature of the mechanics of vehicle structure, frontal stiffness is not a properly defined metric. This research is aimed at developing a well defined method to quantify frontal stiffness for vehicle-to-vehicle crash compatibility. The method to be developed should predict crash outcome and controlling the defined metric should improve the crash outcome. The criterion that is used to judge the aggressivity of a vehicle in this method is the amount of deformation caused to the vulnerable vehicles when crashed with the subject vehicle.

The two main motivations for Wayne State University (WSU) and Henry Ford Hospital (HFH) researchers to develop numerical human surrogates are advanced computing technology and a high-speed x-ray imaging device not available just a decade ago. This paper summarizes the capabilities and limitations of detailed component models of the human body, from head to foot, developed at WSU over the last decade (Zhang et al. 2001, Yang et al. 1998, Shah et al. 2001, Iwamoto et al. 2000, Lee et al. 2001 and Beillas et al. 2001). All of these models were validated against global response data obtained from relevant high-speed cadaveric tests. Additionally, some models were also validated against local kinematics of bones or soft tissues obtained using the high-speed x-ray system. All of these models have been scaled to conform to the key dimensions of a 50th percentile male.

The U.S. Department of Transportation-sponsored Crash Injury Research and Engineering Network (CIREN) program offers a reasonable look at the efficacy of second-generation air bags. This paper examines the data from the William Lehman Injury Research Center (WLIRC). The WLIRC data is a near census of crashes in the Miami-Dade region with occupants that appear to be severely injured. The percentage of deaths among trauma patients in the WLIRC data as a function of delta-V for first-generation air bags was higher than expected at lower delta-V's. There were nine driver fatalities at delta-V's of less than 20 mph (four involving short stature occupants, four with elderly occupants, and one due to significant intrusion and/or vehicle incompatibility). The data supported NHTSA's conclusion that first-generation air bags were too aggressive for occupants in close proximity to the deploying air bag and too aggressive for older persons.

Experimentally derived brain response envelopes are needed to evaluate and validate existing finite element (FE) head models. Motion of the brain relative to the skull during rotational input was measured using high-speed biplane x-ray. To generate repeatable, reproducible, and scalable data, methods were developed to reduce experimental variance. An “extreme-energy” device was developed to provide a controlled input that is unaffected by specimen characteristics. Additionally, a stereotactic frame was used to deploy radiopaque markers at specific, pre-determined locations within the brain. One post-mortem human surrogate (PMHS) head specimen was subjected to repeat tests of a half-sine rotational speed pulse in the sagittal plane. The desired pulse had a peak angular speed of 40 rad/s and duration of 30 ms. Relative motion of the brain was quantified using radiopaque targets and high-speed biplane x-ray. Frontal and occipital intracranial pressure (ICP) were also measured.

The research question investigated in this study is what are the key attributes of foot and ankle injury in the between-rail frontal crash? For the foot and ankle, what was the type of interior surface contacted and the type of resulting trauma? The method was to study with in-depth case reviews of NASS-CDS cases where a driver suffered an AIS=2 foot or ankle injury in between-rail crashes. Cases were limited to belted occupants in vehicles equipped with air bags. The reviews concentrated on coded and non-coded data, identifying especially those factors contributing to the injuries of the driver's foot/ankle. This study examines real-world crash data between the years 1997-2009 with a focus on frontal crashes involving 1997 and later model year vehicles. The raw data count for between-rail crashes was 732, corresponding to 227,305 weighted, tow-away crashes.

Automatic Crash Notification (ACN) technology provides an opportunity to rapidly transmit crash characteristics to emergency care providers in order to improve timeliness and quality of care provided to occupants in the post crash phase. This study evaluated the relative value of crash attributes in providing useful information to assist in the identification of crashes where occupants may be seriously injured. This identification includes an indication of whether a crash is likely to require a level of emergency response with higher priority than is needed for most crashes reported by ACN Systems. The ability to predict serious injury using groupings of variables has been determined. In this way, the consequence of not transmitting each variable can be estimated. In addition, the incremental benefit of voice communication is shown.

This paper investigates the effects of driver airbag inflation characteristics, airbag relative position, airbag to dummy relative velocity, and steering column characteristics using a finite element model of a vehicle, air bag, and Hybrid III 50% male dummy. Simulation is conducted in a static test environment using a validated finite element model. Several static simulation tests are performed where the air bag module's position is mounted in a rigid steering wheel and the vertical and horizontal distances are varied relative to the dummy. Three vertical alignments are used: one position corresponds to the head centered on module, another position corresponds to the neck centered on module, and the third position centers the chest on the module. Horizontal alignments vary from 0 mm to 50 mm to 100 mm. All of these tests are simulated using a typical pre-1998 type inflation curve (mass flow rate of gas entering the bag).

Beginning in model year 1997, BMW introduced an innovative head protection system HPS called the Inflatable Tubular Structure (HPS). Tests indicate that the system dramatically reduces the severity of head impacts in side crashes. This investigation is an evaluation of casualty abatement benefits that are derived from applying injury measures based on the HPS test results to the population in US National Accident Sampling System (NASS/CDS). The results of component and vehicle crash tests are summarized. The procedures for estimating benefits are described along with the benefits in terms of injuries mitigated, maximum injuries to occupants mitigated, and fatalities prevented.

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.

The William Lehman Injury Research Center has conducted multi-disciplinary investigations of one hundred seventy-eight crashes involving adult occupants protected by safety belts and air bags. In all cases, serious injuries were suspected. Nine cases involved serious heart injuries. These cases are not representative of crashes in general. However, when used in conjunction with National Accident Sampling System; Crashworthiness Data System (NASS/CDS) they provide insight into the most severe injuries suffered by restrained occupants in frontal crashes. Heart injuries are rare, but when they occur they are usually life threatening. NASS/CDS shows that heart injuries comprise about 0.2% of the injuries in frontal tow-away crashes. In the NHTSA file of Special Crash Investigations (SCI) of air bag cases, heart injuries are reported in 1% of the occupants over 15 years of age. Twenty-five percent of the fatally injured occupants had heart injuries, and 83% of those with heart injury died.

While the present air bag systems have been shown to be highly effective in high severity crashes, undesirable side effects have been reported in some low severity events. The inflation rate of the airbag during deployment has been cited as a factor which induces injuries. A rapid airbag deployment rate is advantageous to provide protection to occupants in severe crashes. On the other hand, airbag aggressivity associated with the high inflation rate can increase injuries in the lower severity crashes. The injury producing forces from the airbag increase as the occupant position becomes closer to the bag at the time of deployment. This paper describes the results of an analytical study to evaluate chest injury measures for reduced inflation rates of a Taurus type air bag in a variety of crash modes. A detailed nonlinear finite element model of an unfolding airbag and a 50th percentile male Hybrid III dummy are used in conjunction with a test buck to simulate frontal crashes.

One of the leading causes of death in automotive crashes is traumatic rupture of the aorta (TRA) or blunt aortic injury (BAI). The risk of fatality is high if an aortic injury is not detected and treated promptly. The objective of this study is to investigate TRA mechanisms using finite element (FE) simulations of reconstructed real-world accidents involving aortic injury. For this application, a case was obtained from the William Lehman Injury Research Center (WLIRC), which is a Crash Injury Research and Engineering Network (CIREN) center. In this selected crash, the case vehicle was struck on the left side with a Principal Direction of Force (PDoF) of 290 degrees. The side structure of the case vehicle crushed a maximum of 0.33 m. The total delta-V was estimated to be 6.2 m/s. The occupant, a 62-year old mid-sized male, was fatally injured. The occupant sustained multiple rib fractures, laceration of the right ventricle, and TRA, among other injuries.