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Technical Paper

Three-Year-Old Child Out-Of-Position Side Airbag Studies

A series of twenty-nine tests was completed by conducting static deployment of side airbag systems to an out-of-position Hybrid III three-year-old dummy. Mock-ups (bucks) of vehicle occupant compartments were constructed. The dummy was placed in one of four possible positions for both door- and seat-mounted side airbag systems. When data from each type of position test were combined for the various injury parameters it was noted that the head injury criteria (HIC) were maximized for head and neck tests, and the chest injury parameters were maximized for the chest tests. For the neck injury parameters, however, all of the test positions produced high values for at least one of the parameters. The study concluded the following. Static out-of- position child dummy side airbag testing is one possible method to evaluate the potential for injury for worst-case scenarios. The outcome of these tests are sensitive to preposition and various measurements should be made to reproduce the tests.
Technical Paper

Thoracic Trauma Assessment Formulations for Restrained Drivers in Simulated Frontal Impacts

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.
Technical Paper

Thoracic Injury Prediction via Digital Convolution Theory

A dynamic characterization of the human thorax, in the form of a digital impulsive response signature, has been obtained which links the acceleration response of the struck side with the far side of the thorax under side impact conditions. This dynamic characterization was obtained by a unique combination of digital convolution theory, least squares approximation techniques, and a digital set of cadaver impact data. It has proven itself accurate in predicting the maximum relative acceleration, velocity and displacement between the left and the right lateral aspects of the thorax for a variety of impact conditions including lateral pendulum impacts, lateral rigid walls impacts at 15 and 20 mph and lateral impacts into padded walls at 20 mph.
Technical Paper

The Effects of Axial Preload and Dorsiflexion on the Tolerance of the Ankle/Subtalar Joint to Dynamic Inversion and Eversion

Forced inversion or eversion of the foot is considered a common mechanism of ankle injury in vehicle crashes. The objective of this study was to model empirically the injury tolerance of the human ankle/subtalar joint to dynamic inversion and eversion under three different loading conditions: neutral flexion with no axial preload, neutral flexion with 2 kN axial preload, and 30° of dorsiflexion with 2 kN axial preload. 44 tests were conducted on cadaveric lower limbs, with injury occurring in 30 specimens. Common injuries included malleolar fractures, osteochondral fractures of the talus, fractures of the lateral process of the talus, and collateral ligament tears, depending on the loading configuration. The time of injury was determined either by the peak ankle moment or by a sudden drop in ankle moment that was accompanied by a burst of acoustic emission. Characteristic moment-angle curves to injury were generated for each loading configuration.
Technical Paper


Axial loading of the foot/ankle complex is an important injury mechanism in vehicular trauma that is responsible for severe injuries such as calcaneal and tibia pilon fractures. Axial loading may be applied to the leg externally, by the toepan and/or pedals, as well as internally, by active muscle tension applied through the Achilles tendon during pre-impact bracing. In order to evaluate the effect of active muscle tension on the injury tolerance of the foot/ankle complex, blunt axial impact tests were performed on 44 isolated lower legs with and without experimentally simulated Achilles tension. The primary fracture mode was calcaneal fracture in both groups, but tibia pilon fractures occurred more frequently with the addition of Achilles tension. Acoustic emission demonstrated that fracture initiated at the time of peak local axial force.
Technical Paper

Side Impact - The Biofidelity of NHTSA's Proposed ATD and Efficacy of TTI

A number of tests conducted under the sponsorship of the FAT were reported in papers at two previous Stapp Conferences and an Experimental Safety Vehicle Conference. These tests featured human cadavers and three different Anthropomorphic Test Devices (ATD) designed for use in lateral impacts. Test subjects were placed in Opel car bodies and impacted laterally by CCMC moving deformable barriers. In the previous papers, the reported responses of the human cadavers had wide variability and none of the ATD's studied featured good biofidelity. In this effort, a reexamination of the available data was undertaken and the process and results of applying different analysis techniques to the cadaver data, which resulted in significantly reduced scatter and variability, are discussed. Comparisons of the impact responses of the cadavers and the NHTSA developed Side Impact Dummy are also made.
Technical Paper

Response of the Eurosid-1 Thorax to Lateral Impact

The Eurosid-1 dummy was subjected to a series of lateral and oblique pendulum impacts to study the anomalous “flat-top” thorax deflection versus time-histories observed in full-scale vehicle tests. The standard Eurosid-1, as well as two different modified versions of the dummy, were impacted at 6 different angles from -15 to +20 degrees (0 degrees is pure lateral) in the horizontal plane. The flat-top deflections were observed in the tests with the standard Eurosid-1, while one of the modified versions reduced the flat-top considerably. Full scale vehicle tests with the standard and modified Eurosid-1 suggest similar reductions. A second series of tests was conducted on the modified Eurosid-1 to investigate the effect of door surface friction on the shoulder rotation and the chest deflection. The data suggested that increasing the friction on the door surface impeded shoulder rotation and ultimately reduced the chest deflection in the Eurosid-1.
Technical Paper

Response and Tolerance of the Human Forearm to Impact Loading

With the widespread use of supplemental restraint systems (airbags), occasional rare injuries have occurred because of the force associated with these systems upon deployment. Recent case studies have demonstrated forearm fractures associated with airbag deployment. The present study was conducted to determine the tolerance of the human forearm under a dynamic bending mode. A total of 30 human cadaver forearm specimens were tested using three-point bending protocol to failure at 3.3 m/s and 7.6 m/s velocities. Results indicated significantly (p < 0.01) greater biomechanical parameters associated with males compared to females. The bending tolerance of the human forearm, however, was found to be most highly correlated to bone mineral density, bone area, and forearm mass. Thus, any occupant with lower bone mineral density and lower forearm geometry/mass is at higher risk. The mean failure bending moment for all specimens was 94 Nm.
Technical Paper

Response Corridors of Human Surrogates in Lateral Impacts

Thirty-six lateral PMHS sled tests were performed at 6.7 or 8.9 m/s, under rigid or padded loading conditions and with a variety of impact surface geometries. Forces between the simulated vehicle environment and the thorax, abdomen, and pelvis, as well as torso deflections and various accelerations were measured and scaled to the average male. Mean ± one standard deviation corridors were calculated. PMHS response corridors for force, torso deflection and acceleration were developed. The offset test condition, when partnered with the flat wall condition, forms the basis of a robust battery of tests that can be used to evaluate how an ATD interacts with its environment, and how body regions within the ATD interact with each other.
Technical Paper

RAID - An Investigative Tool to Study Air Bag/Upper Extremity Interactions

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.
Technical Paper

Quantification of Side Impact Responses and Injuries

Side impacts have been shown to produce a large portion of both serious and fatal injuries within the total automotive crash problem. These injuries are produced as a result of the rapid changes in velocity an automobile occupant's body experiences during a crash. Any improvement to the side impact problem will be brought about by means which will ultimately modify the occupant's rapid body motions to such a degree that they will no longer produce injuries of serious consequence. Accurate knowledge of both the body's motion and resulting injuries under a variety of impact conditions is needed to achieve this goal. Possession of this knowledge will then permit development of accurate anthropomorphic test devices and injury criteria which can be used to create effective injury countermeasures in vehicles.
Technical Paper

Production of Injury in Blunt Frontal Impact

Blunt thoracic impact as experienced by automobile occupants in frontal impact has received considerable research attention over the past 20 years. These efforts have provided the basis for the development of test dummy impact response specifications as well as evaluation criteria to be used in conjunction with the dummy to evaluate the hazard of various crash situations. This paper will attempt to extend the current understanding if thoracic injury production by examining the results of 82 impact tests to determine the effects that several fundamental parameters have on the production of injuries in the thorax.
Technical Paper

Prediction of Brain Injury Measures from Head Motion Parameters

An analysis of experimental head impact data was preformed to demonstrate: (1) that kinematic waveforms contain information relating to head and brain injuries; and (2) that analysis techniques exist which can properly exploit this information to create injury predictive functions. An experimental data base consisting of 26 monkey head impacts was utilized. Translational and rotational acceleration time histories of the head were available. Parameters computed from these kinematic waveforms were the input variables to an analysis technique. The output, or modeled, variable was the experimentalist's evaluation of the severity of injuries. The results of the analysis are presented and it is concluded that it is possible to accurately model head and brain injury assessments from strictly head motion parameters.
Technical Paper

Optimal Design of Automobiles for Pedestrian Protection

A system of computer programs has been developed to simulate the injuries suffered by a pedestrian struck by an automobile. The system provides a semi-automatic search for safer hood/grille/bumper configurations and stiffnesses. After the software system was developed, three major optimizations, interspersed with modeling changes to improve the accuracy of the simulations, were performed. Results from the optimization series were used to help design full-scale impact tests using child and adult dummies. In turn, experimental measurements were used to improve the mathematical model of the impact simulator. The results of these studies have provided some insights into vehicle design parameters which produce safer vehicles.
Technical Paper

On the Development of the SIMon Finite Element Head Model

The SIMon (Simulated Injury Monitor) software package is being developed to advance the interpretation of injury mechanisms based on kinematic and kinetic data measured in the advanced anthropomorphic test dummy (AATD) and applying the measured dummy response to the human mathematical models imbedded in SIMon. The human finite element head model (FEHM) within the SIMon environment is presented in this paper. Three-dimensional head kinematic data in the form of either a nine accelerometer array or three linear CG head accelerations combined with three angular velocities serves as an input to the model. Three injury metrics are calculated: Cumulative strain damage measure (CSDM) – a correlate for diffuse axonal injury (DAI); Dilatational damage measure (DDM) – to estimate the potential for contusions; and Relative motion damage measure (RMDM) – a correlate for acute subdural hematoma (ASDH).
Technical Paper

On the Development of a Deformation Measurement System and Its Application Toward Developing Mechanically Based injury Indices

The External Peripheral Instrument for Deformation Measurement (EPIDM) system is composed of a sensing device and an analysis process which determines the complete geometric description of the periphery of a cross-section of a body as it deforms or is deformed in time. The sensing device is a band attached to the surface of the deformable body along the external peripheral path of the desired geometrical cross-section. The analysis process utilizes the output from strategically located sensors along the length of the band to calculate and develop the contour of the body to which it is attached.
Technical Paper

On the Development of Survival Criteria for Rate Sensitive Materials

The evaluation and mitigation of injury in the automotive crash environment is often achieved by monitoring and limiting the magnitude of forces and/or moments being applied to or transmitted through dummy structures representing particular portions of the human anatomy. Examples of body areas where this is the practice are the neck, the thoracic and lumbar spine, the pelvis, as well as the upper and lower extremities. Implicit within this process is the assumption that the observed forces are directly proportional to local failure metrics such as stress and/or strain. However, a variety of experimental efforts have demonstrated that many of these anatomical structures exhibit, to various degrees, viscoelastic behavior and time or rate dependent failure properties. This work develops a methodology that generalizes the results of various experimental observations.
Technical Paper

Mechanisms and Factors Involved in Hip Injuries During Frontal Crashes

This study was conducted to collect data and gain insights relative to the mechanisms and factors involved in hip injuries during frontal crashes and to study the tolerance of hip injuries from this type of loading. Unembalmed human cadavers were seated on a standard automotive seat (reinforced) and subjected to knee impact test to each lower extremity. Varying combinations of flexion and adduction/abduction were used for initial alignment conditions and pre-positioning. Accelerometers were fixed to the iliac wings and twelfth thoracic vertebral spinous process. A 23.4-kg padded pendulum impacted the knee at velocities ranging from 4.3 to 7.6 m/s. The impacting direction was along the anteroposterior axis, i.e., the global X-axis, in the body-fixed coordinate system. A load cell on the front of the pendulum recorded the impact force. Peak impact forces ranged from 2,450 to 10,950 N. The rate of loading ranged from 123 to 7,664 N/msec. The impulse values ranged from 12.4 to 31.9 Nsec.
Technical Paper

International Harmonized Research Activities (IHRA) status report of the Biomechanics Working Group

A summary of the efforts of the Biomechanics Working Group to complete the task given to it by the International Harmonized Research Activities Steering Committee to determine specifications for a Universal Side Impact Anthropomorphic Test Devices is presented. Topics discussed are the nature of the world side impact problem, the anthropometric characterization of the world population at risk, dummy impact response specifications, and necessary and appropriate injury criteria and performance levels.
Technical Paper

Interaction of Human Cadaver and Hybrid III Subjects with a Steering Assembly

Nineteen sled impact tests were conducted simulating a frontal collision exposure for an unrestrained driver. The deceleration sled buck configuration utilized the passenger compartment of a late model compact passenger vehicle, a rigid driver's seat, and a custom fabricated energy-absorbing steering column and wheel assembly. Sled impact velocities ranged from 24.1 to 42.6 km/hr. The purpose of the study was to investigate the kinematic and kinetic interaction of the driver and the energy-absorbing steering assembly and their relationship to the thoracic/abdominal injuries produced. The similarities and differences between human cadaver and anthropomorphic dummy subjects were quantified.