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This paper details the development of an abdominal injury assessment device for loading due to belt restraint submarining in the Hybrid III family of dummies. The design concept and criteria, response criteria, choice of injury criterion, and validation are explained. Conclusions of this work are: 1) Abdominal injury assessment for belt loading due to submarining is now possible in the Hybrid III family of dummies. 2) The abdomen developed has biofidelity in its force deflection characteristics for belt loading, is capable of detecting the occurrence of submarining, and can be used to determine the probability of abdominal injury when submarining occurs. 3) Installation of the abdomen in the Hybrid III dummy does not change the dummy kinematics when submarining does not occur. 4) When submarining does occur, the dummy kinematics are very similar to baseline Hybrid III kinematics, except for torso angle.

The purpose of this study was to investigate approaches evaluating the performance of safety systems in crash tests and by analytical simulations. The study was motivated by the need to consider the adequacy of injury criteria and tolerance levels in FMVSS 208 measuring safety performance of restraint systems and supplements. The study also focused on additional biomechanical criteria and performance measures which may augment FMVSS 208 criteria and alternative ways to evaluate dummy responses rather than by comparison to a tolerance level. Additional analysis was conducted of dummy responses from barrier crash and sled tests to gain further information on the performance of restraint systems. The analysis resulted in a new computer program which determined several motion and velocity criteria from measurements made in crash tests.

Blunt impacts to the back of the torso can occur in vehicle crashes due to interaction with unrestrained occupants, or cargo in frontal crashes, or intrusion in rear crashes, for example. Six pendulum tests were conducted on the back of an instrumented 50th percentile male Hybrid III ATD (Anthropomorphic Test Device) to determine kinematic and biomechanical responses. The impact locations were centered with the top of a 15-cm diameter impactor at the T1 or at T6 level of the thoracic spine. The impact speed varied from 16 to 24 km/h. Two 24 km/h tests were conducted at the T1 level and showed repeatability of setup and ATD responses. The 16 and 24 km/h tests at T1 and T6 were compared. Results indicated greater head rotation, neck extension moments and neck shear forces at T1 level impacts. For example, lower neck extension was 2.6 times and 3.8 times greater at T1 versus T6 impacts at 16 and 24 km/h, respectively.

Side impact pendulum tests were conducted on Eurosid I and Biosid to assess the biofidelity of the thorax, abdomen and pelvis, and determine injury tolerance levels. Each body region was impacted at 4.5, 6.7, and 9.4 m/s using test conditions which duplicate cadaver impacts with a 15 cm flat-circular 23.4 kg rigid mass. The cadaver database establishes human response and injury risk assessment in side impact. Both dummies showed better biofidelity when compared to the lowest-speed cadaver response corridor. At higher speeds, peak force was substantially higher. The average peak contact force was 1.56 times greater in Biosid and 2.19 times greater in Eurosid 1 than the average cadaver response. The Eurosid I abdomen had the most dissimilar response and lacks biofidelity. Overall, Biosid has better biofidelity than Eurosid I with an average 21% lower peak load and a closer match to the duration of cadaver impact responses for the three body regions.

Knee bolsters on the lower instrument panel have been designed to control occupant kinematics during sudden deceleration. However, a wide variability in car occupant anthropometry and choice of seating posture indicates that lower-extremity contacts with the impingement bolster could predominantly load the flexed leg through the knee (acting through the femur) or through the tibia (acting through the knee joint). Potential injuries associated with these types of primary loading may vary significantly and an understanding of potential trauma mechanisms is important for proper occupant restraint.

The timing of liver laceration in swine during the course of a blunt impact was investigated. The swine were impacted on the upper abdomen by the lower segment of a steering wheel at 6, 9 and 12 m/s. The degree of compression in each impact was controlled independently from 10 to 50%. By varying when “the punch of an impact was pulled,” we reproduced progressive segments of a longer duration blunt impact. Autopsy of the subjects demonstrated that lacerations were initiated after 8 ms of loading at 9 m/s and 6 ms of loading at 12 m/s. The time of injury was concurrent with the time when the Viscous response exceeded a threshold of 1.2 m/s in our specimens. The Viscous injury criterion, defined as the peak Viscous response, was found to be the best predictor of liver laceration. We conclude that the Viscous response relates to the actual etiology of injury, in addition to being an excellent correlative measure.

Barrier crash simulations with a torsobelted Part 572 dummy were conducted to determine the influence of knee bolster crush orientations of 0°–60° on lower extremity restraint. Responses from two sled velocity and mean deceleration severities were investigated: 6.6 m/s at 7.5 g and 13.5 m/s at 13.9 g. The dummy’s knees were prepositioned 10 cm from individual experimental bolsters, which crushed along a predetermined axis. Bolster orientation had only a minor effect on the level of peak dummy femur, and resultant knee bolster reaction load and on lower extremity kinematics of the torsobelted occupant; however, the local loading of the knee and level of tibial compression were significantly influenced.

The primary purpose of this parameter study was to carefully document occupant dynamics in well-controlled sled tests for comparison with simulated responses from the MVMA-2D analytical model. The test involved a Part 572 dummy exposed to a frontal deceleration while on a bucket seat and restrained by a lap-shoulder belt system. The length of belt webbing was incrementally increased from a snug configuration by as much as 30 cm. The addition of webbing increased the forward excursion, velocity, and acceleration of the head, chest, and hip without affecting the peak tension in the belt segments of the restraint system. Belt tension was identified as a poor measure of the horizontal load on the chest due to significant reaction forces in the lateral and vertical direction at the belt anchorages.

Sled tests were conducted at farside oblique angles of 15°, 45°, and 75° with a Part 572 dummy restrained by a conventional driver lap/shoulder belt system or a preinflated driver inflatable restaint. Occupant dynamics were compared in similar tests where an inboard energy absorbing lateral restraint of the upper torso was or was not used. It can be concluded that the seat wing improves the control of the dummy's dynamics in oblique impacts by directing the occupant's motion more forward into the restraint system, thereby taking more advantage of the restraining potential of the shoulder belt or inflatable restraint in controlling the deceleration of the dummy and enhancing the benefit of the restraint system. However, additional factors associated with the use of a seat wing remain to be investigated including the effect of impact force on the occupant, interaction with out-of-position occupants and comfort/convenience.

Objective: This study analyzes rear sled tests with a 95th% male and 5th% female Hybrid III dummy in various seating positions on ABTS (All Belt to Seat) seats in severe rear impact tests. Dummy interactions with the deforming seatback and upper body extension around the seat frame are considered. Methods: The 1st series involved an open sled fixture with a Sebring ABTS seat at 30 mph rear delta V. A 95th% Hybrid III dummy was placed in four different seating positions: 1) normal, 2) leaning inboard, 3) leaning forward and inboard, and 4) leaning forward and outboard. The 2nd series used a 5th% female Hybrid III dummy in a Grand Voyager body buck at 25 mph rear delta V. The dummy was leaned forward and inboard on a LeSabre ABTS or Voyager seat. The 3rd series used a 5th% female Hybrid III dummy in an Explorer body buck at 26 mph rear delta V. The dummy was leaned forward and inboard on a Sebring ABTS or Explorer seat.

Various surrogates and responses are available for study of the impact performance of energy absorbing steering systems in the laboratory. The relative influence of the SAE J-944 body block, the Part 572 dummy, and the GM Hybrid III dummy and of the associated thoracic responses were investigated for steering assembly impact in a series of sled tests. Not only did response amplitudes differ among the surrogates but more importantly trends in impact performance associated with modifications of the steering assembly depended on the choice of surrogate and response. The Hybrid III dummy was judged the best of the tested surrogates for study of the steering system impact performance in the laboratory, based on its more humanlike construction, impact response and expanded measurement capacity.

The study was directed toward improving our understanding how postcrash column compression and steering wheel deformation relate to the driver interaction with an energy absorbing steering system during automotive collisions. Frontal sled tests conducted at 19–37 km/h investigated the Part 572 antropomorphic dummy interaction with a ball-sleeve column steering assembly over a range of column angles and surrogate postures. Neither column compression nor steering wheel deformation correlated with the mechanical severity of the test surrogate interaction with the steering system. The steering wheel deformed before the column compressed and the degree of wheel deformation strongly depended on the surrogate load distribution, the steering wheel being an important energy absorbing element.

Active head restraints are being used to reduce the risk of whiplash in rear crashes. However, their evaluation in laboratory tests can vary depending on the injury criteria and test dummy. The objective of this study was to conduct barrier tests with BioRID and sled tests with Hybrid III to determine the most meaningful responses related to whiplash risks in real-world crashes. This study involved: (1) twenty-four rear barrier tests of the Saab 9000, 900, 9-3 and 9-5 with two fully instrumented BioRID dummies placed in the front or rear seats and exposed to 24 and 48.3 km/h barrier impacts, and (2) twenty rear sled tests at 5-38 km/h delta V in three series with conventional, modified and SAHR seats using the Hybrid III dummy. A new target superposition method was used to track head displacement and rotation with respect to T1. Insurance data on whiplash claims was compared to the dummy responses.

The objective of this study was to analyze available anthropomorphic test device (ATD) responses from FMVSS 301-type rear impact tests. Rear impact test data was obtained from NHTSA and consisted of dummy responses, test observations, photos and videos. The data was organized in four test series: 1) NCAP series of 30 New Car Assessment Program tests carried out at 35 mph with 1979-1980 model year vehicles, 2) Mobility series of 14 FMVSS 301 tests carried out at 30 mph with 1993 model year vehicles, 3) 301 MY 95+ series of 79 FMVSS 301 tests carried out at 30 mph with 1995-2005 model year vehicles and 4) ODB series of 17 Offset Deformable Barrier tests carried out at 50 mph with a 70% overlap using 1996-1999 model year vehicles. The results indicate very good occupant performance in yielding seats in the NCAP, Mobility and 301 MY 95+ test series.

Previous pendulum impact tests have shown that knee joint injuries and tibial-fibular fractures may occur when loads are directed against the lower leg rather than directly against the femur in the knee. In order to further improve our understanding of lower extremity restraint mechanics, simulated frontal barrier crash experiments were conducted with unembalmed human cadavers and an anthropomorphic dummy restrained by a two-point shoulder belt. In the first test, an experimental bolster was specifically positioned so that the cadaver's lower leg would strike the bolster, thus inducing restraining loads entirely below the knee joint. The analysis of occupant kinematics showed that the flexed knee rode over and forward of the low-positioned bolster. Restraint induced considerable shearing load across the knee joint. Bolster measurements indicated a peak load of approximately 4.0 kN per leg which resulted in a contralateral central tear of the posterior cruciate ligaments.

Objective: This study analyzed available rear impact sled tests with Starcraft-type seats that use a diagonal belt behind the seatback. The study focused on neck responses for out-of-position (OOP) and in-position seated dummies. Methods: Thirteen rear sled tests were identified with out-of-position and in-position 5 th , 50 th and 95 th Hybrid III dummies in up to 47.6 mph rear delta Vs involving Starcraft-type seats. The tests were conducted at Ford, Exponent and CSE. Seven KARCO rear sled tests were found with in-position 5 th and 50 th Hybrid III dummies in 21.1-29.5 mph rear delta Vs involving Starcraft-type seats. In all of the in-position and one of the out-of-position series, comparable tests were run with production seats. Biomechanical responses of the dummies and test videos were analyzed.

This study analyzed FMVSS 301 rear impact tests with an instrumented rear-seat dummy. NHTSA conducted 15 FMVSS 301 rear crash tests with an instrumented and belted 50th Hybrid III dummy in the rear seat. In series 1, there were three repeat tests with the Jeep Liberty and two others, but no onboard camera view. In series 2, there were 8 tests with 2003-2005 MY (model year) vehicles that had rear head restraints. In series 3, there were two tests with 2004-2005 MY vehicles that did not have rear head restraints. There was an onboard camera view of the rear occupant in series 2 and 3. The dummy responses were evaluated and compared to relevant IARVs (injury assessment reference values). Based on the HRMD, the average height of the rear head restraints was 80.4 ± 3.4 cm (31.6″ ± 1.3″) above the H-point. In series 1, the delta V was 24.4 ± 2.0 km/h (15.2 ± 1.3 mph).

This sled test series involved occupant loading of the seat in rear crashes of 4.3-8.3 m/s (9.6-18.5 mph). The tests were conducted in the early 1980s and involved an unbelted or lap-shoulder belted Part 572 dummy in rear and oblique rear impacts. The research is reported today to provide comparative data for the record and serves as a control benchmark for more current technologies and safety research methodologies on seat performance in rear crashes. Safety belts improved occupant retention on the seat primarily by the lap belt reducing the upward and rearward movement of the pelvis. Tests were also conducted on the mechanisms for energy absorption by seatback deflection.

Role of the Seat in Rear Crash Safety addresses the historic debate over seatback stiffness, energy absorbing yielding, occupant retention and whiplash prevention; and it provides a scientific foundation for the direction GM pursued in the development and validation of future seat designs. It also describes the multi-year research study into the role of the seat in rear crash safety - first by addressing the need for occupant retention in the more severe rear crashes; and then by addressing the needs for an adequately positioned head restraint and changes in the compliance of the seatback to lower the risks of the whiplash in low-speed crashes.

The objective of this study was to analyze available anthropomorphic test device (ATD) responses from KARCO rear impact tests and to evaluate an injury predictive model based on crash severity and occupant weight presented by Saczalski et al. (2004). The KARCO tests were carried out with various seat designs. Biomechanical responses were evaluated in speed ranges of 7-12, 13-17, 18-23 and 24-34 mph. For this analysis, all tests with matching yielding and stiff seats and matching occupant size and weight were analyzed for cases without 2nd row occupant interaction. Overall, the test data shows that conventional yielding seats provide a high degree of safety for small to large adult occupants in rear crashes; this data is also consistent with good field performance as found in NASS-CDS. Saczalski et al.'s (2004) predictive model of occupant injury is not correct as there are numerous cases from NASS-CDS that show no or minor injury in the region where serious injury is predicted.