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Pedestrian research and testing at the NHTSA Vehicle Research and Test Center has recently focused on assessment of proposed ISO and EEVC head impact test procedures, and extension of these procedures to additional vehicle frontal surfaces. In addition to test parameter sensitivity evaluation, reconstruction of PCDS (Pedestrian Crash Data Study) cases with laboratory impact tests and computer simulations has been conducted. This paper presents the results of this research.

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.

This paper describes the development of a free-motion headform which was designed to permit the simulation of head impacts common in the automotive crash environment. A Hybrid III headform was modified allowing it to be propelled in free flight at up to 64.4 km/h velocities. The headform was also instrumented with a nine-accelerometer array to permit the calculation of rotational accelerations. Tests were conducted to determine the repeatability and sensitivity of the device, and component test results were compared with results from a full scale crash test in which Hybrid III dummies were used. Comparisons are also made with accident investigation information obtained from the NHTSA Washington Hospital Trauma Center study.

Two computer models, ABAG 19 and HSRI-3D, were validated against experimental data to determine and compare their capability for simulating the responses of air bag restrained automobile occupants in severe frontal collisions. Standard sets of model input parameters were developed for both driver and passenger. The primary objective was to determine which model was best suited for determining potential crashworthiness in a large number of production vehicles. Advantages and disadvantages of the models were determined, using criteria such as accuracy, ease of use, quality of documentation and user orientation.

Frontal sled tests of the Part 572, APR, and Hybrid III dummies were conducted in a three-point restraint system at 50 km/hr velocity change. The tests were conducted to evaluate the dummy responses in a tightly controlled systems environment, and to compare the dummy responses to previously established cadaver responses from the same environment. The Hybrid III dummy measurement repeatability was found to be better than either the Part 572 or APR dummies, although the thoracic acceleration responses from all three are shown to be quite similar to cadavers. Correlation of the dummy measurements are made to a limited amount of both the cadaver data and accident data from the National Crash Severity Study.

Three groups of crash tests were analyzed to determine how well the standard fixed rigid barrier measures potential crash survivability in small cars when impacted full frontally by larger cars. In addition to experimental results, simple analytical methods were used to determine and compare the level of occupant protection in the small cars. The fixed rigid barrier appears to be an accurate crashworthiness-measuring device for small cars in high speed full frontal car/car collisions, if test velocities are selected on the basis of equivalent energy between car/barrier and car/car collisions as opposed to equivalent momentum.

This paper presents the initial results of a crash test program designed to evaluate the ability of three different barriers to measure vehicle aggressiveness. The barriers included in the study are the fixed rigid (FRB), load cell fixed (LCFB) and moving deformable (MDB). Previous crash tests and analytical studies conducted to determine causes of aggressiveness and ways of measuring aggressiveness are reviewed. In this paper, full frontal car-to-car and FRB crash test results of an aggressive and a non-aggressive car are presented and compared.

This paper presents an analysis of the results of a series of crash tests conducted by the NHTSA to identify structural parameters contributing to vehicle aggressiveness in frontal collisions between large and small cars. Effects of front structure stiffness, engine mass and engine position were investigated. In addition, an analytical study of car-to-car and car-to-barrier crashes is reported. A lumped parameter car model was used with multiple linear regression analysis to determine the significance of specific vehicle parameters on aggressiveness, and the capabilities of different types of barriers to “measure” that aggressiveness.