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This paper presents the results of biomechanical testing of the SID-IIs beta+-prototype dummy by the Occupant Safety Research Partnership. The purpose of this testing was to evaluate the dummy against its previously established biomechanical response corridors for its critical body regions. The response corridors were scaled from the 50th percentile adult male corridors defined in International Standards Organization Technical Report 9790 to corridors for a 5th percentile adult female, using established International Standards Organization procedures. Tests were performed for the head, neck, shoulder, thorax, abdomen and pelvis regions of the dummy. Testing included drop tests, pendulum impacts and sled tests. The biofidelity of the SID-IIs beta+-prototype was calculated using a weighted biomechanical test response procedure developed by the International Standards Organization.

The SID-IIs side impact dummy is a newly designed dummy as an anthropomorphic test device for small size person to be used in side impact crash testing. The head and neck are one of the key components for SID-IIs dummy designing, manufacturing, and testing. This paper is focused on the development of a Headform to be used for neck calibration of the SID-IIs side impact dummy. It will be very difficult in neck calibration measurement of the SID-IIs dummy if its head is used for the test directly. The Headform is one of the methods to solve this problem. However, the Headform must be consistent in achieving equivalent functional performance as the dummy head and associated physical properties. A 3-D head model has been developed for obtaining initial basic information. The offset can be controlled within 3% during the engineering design of the Headform. The neck dynamic test has been done before the Headform test.

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.

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.

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.

Since 1960 head impact responses under the action of various forces have been studied analytically. However, the effects of force distribution upon head injury mechanisms have not been studied because measurements of force distribution during head impacts have not been experimentally available. In the past, several methods were tested in order to measure head contact pressure, but the results were not very useful. Since the skull is a composite shell structure, the thin shell theory may be valid for stress analysis. According to the theory, the influence of an external load on a shell element damps out rapidly as the distance between the load and the element increases. Stress concentrations occur in the shell elements directly under the center core area of a localized external load. Therefore, the force on the center core, not the entire force distribution, is critical for the assessment of skull responses.

Head injuries are considered a significant safety problem for vehicle occupants involved in vehicle crashes. Although medical literature on the subject is extensive, the emphasis is mainly on the clinical and studies frequently involve data samples that are not representative to the vehicle occupant population. Also, research efforts on head injury have focused on the head rotational acceleration mechanism. The effect of head contact on brain injuries has not been adequately acknowledged and there has been disagreement regarding skull fracture and its relationship to brain injury. The human head, being an extremely complex structure, has many independent injury modes which cannot be described satisfactorily by a single brain injury mechanism. Many individual pathophysiological disturbances to the skull and its contents together comprise head injuries.

This paper describes the design and development of a small female crash test dummy, results of biofidelity tests, and preliminary results from full-scale, 3-point belt and airbag type sled tests. The small female THOR was designed using the anthropometric data developed by Robbins for the 5th percentile female and biomechanical requirements derived from scaling the responses of the 50th percentile male. While many of the mechanical components of the NHTSA THOR 50th percentile male dummy were scaled according to the appropriate anthropometric data, a number of improved design features have been introduced in the new female THOR. These include; improved neck design, new designs for the head and neck skins: and new designs for the upper and lower abdomen. The lower leg, ankle and foot, known as THOR-FLx, were developed in an earlier effort and have been included as a standard part of the new female dummy.

Anthropomorphic test devices (ATDs) should accurately depict head kinematics in crash tests, and thoracic spine properties have been demonstrated to affect those kinematics. To investigate the relationships between thoracic spine system dynamics and upper thoracic kinematics in crash-level scenarios, three adult post-mortem human subjects (PMHS) were tested in both Isolated Segment Manipulation (ISM) and sled configurations. In frontal sled tests, the T6-T8 vertebrae of the PMHS were coupled through a novel fixation technique to a rigid seat to directly measure thoracic spine loading. Mid-thoracic spine and belt loads along with head, spine, and pectoral girdle (PG) displacements were measured in 12 sled tests conducted with the three PMHS (3-pt lap-shoulder belted/unbelted at velocities from 3.8 - 7.0 m/s applied directly through T6-T8).

When the Hybrid III 10-year old (HIII-10C) anthropomorphic test device (ATD) was adopted into Code of Federal Regulations (CFR) 49 Part 572 as the best available tool for evaluating large belt-positioning booster seats in Federal Motor Vehicle Safety Standard (FMVSS) No. 213, NHTSA stated that research activities would continue to improve the performance of the HIII-10C to address biofidelity concerns. A significant part of this effort has been NHTSA’s in-house development of the Large Omnidirectional Child (LODC) ATD. This prototype ATD is comprised of (1) a head with pediatric mass properties, (2) a neck that produces head lag with Z-axis rotation at the atlanto-occipital joint, (3) a flexible thoracic spine, (4) multi-point thoracic deflection measurement capability, (5) skeletal anthropometry representative of a seated child, and (6) an abdomen that can directly measure belt loading.

The objective of this study is to present a quantitative comparison of the biofidelity of the THOR and Hybrid III 50th percentile male ATDs. Quantitative biofidelity was assessed using NHTSA’s Biofidelity Ranking System in a total of 21 test conditions, including impacts to the head, face, neck, upper thorax, lower oblique thorax, upper abdomen, lower abdomen, femur, knee, lower leg, and whole-body sled tests to evaluate upper body kinematics and thoracic response under frontal and frontal oblique restraint loading. Biofidelity Ranking System scores for THOR were better (lower) than Hybrid III in 5 of 7 body regions for internal biofidelity and 6 of 7 body regions for external biofidelity. Nomenclature is presented to categorize the quantitative results, which show overall good internal and external biofidelity of the THOR compared to the good (internal) and marginal (external) biofidelity of the Hybrid III.