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Motorized shoulder belt tensioning is a new automotive seatbelt technology which has shown promise to reduce automotive crash injuries. The current study was conducted to determine if the Hybrid III family of dummies is an appropriate biofidelic surrogate for studying motorized shoulder belt tensioning. The objective was to measure torso retraction time, torso position, torso velocity, internal resistive moment, changes in torso curvature and the center of rotation of torso extension during seatbelt tensioning for the Hybrid III family. A previous study developed a protocol and test fixture to measure the biomechanics of volunteers subject to quasi-static loading by a motorized shoulder belt tensioner. A fixture supported the occupant leaning forward and applied shoulder belt tension. Kinematics were quantified by analyzing the motion of reflective markers on the dummy using an eight camera digital video system. A three axis load cell measured internal resistance to extension.

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.

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.

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.

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.

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.

Belt interaction with the dummy's chest or pelvis was investigated during simulated frontal decelerations to develop a better understanding of the mechanics of belt restraint. Hyge sled tests were conducted at acceleration levels of 6-16 g's with a Part 572 dummy forward facing on an automotive bucket seat. Dynamics were compared in similar tests where the dummy was restrained by a conventional shoulder belt or belt segments attached to a modified sternum - a steel sternum with extensions for fixed belt attachments. Tests were also conducted with a conventional lap belt or belt segments fixed to an extension of the H point. Deformation characteristics of the standard and modified thorax were determined for a lateral and superior point load or a belt yoke compression of the sternum. The pelvic structure was also compressed by a lap belt. Our evaluation of test dummy dynamics indicates the following sequence of events with a conventional shoulder belt: 1.)

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.

Five anesthetized porcine subjects were exposed to blunt thoracic impact using a 21 kg mass with a flat contact surface traveling at 3.0 to 12.2 m/s. The experiments were conducted to assess the appropriateness of studying in vivo mechanical and physiological response to thoracic impact in a porcine animal model. A comprehensive review of comparative anatomy between the pig and man indicates that the cardiovascular, respiratory and thoracic skeletal systems of the pig are anatomically and functionally a good parallel of similar structures in man. Thoracic anthropometry measurements document that the chest of a 50 to 60 kg pig is similar to the 50th percentile adult male human, but is narrower and deeper. Peak applied force and chest deflection are in good agreement between the animal's responses and similar impact severity data on fresh cadavers.

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.

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.

An analysis of the MVMA-sponsored full scale side impact tests of modified Ford LTDs indicated that the high, nonhuman-like inertia of the dummy chest had profound influence over the dummy responses. In particular, energy absorbing padding was always crushed by the inertial force when the door impacted the dummy. The heavy axial pistons and dampers in the dummy chest, and the variable arm positions further exacerbated poor repeatibility of the chest deflection responses. Although TTI (d), an acceleration based injury criterion, discriminated the presence of padding and was repeatable, it exaggerated the potential benefits of padding in injury mitigation. Analysis of the data also indicated that the structural enhancement performed on the LTDs did not reduce the door intrusion velocity consistently in the tests. Consequently, dummy responses were not influenced by the structural enhancement.

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.

The discovery of the mechanism of impact-induced soft tissue injury has led to our introduction of a Viscous Injury Criterion, which predicts the severity and the time of occurrence of soft tissue injury induced by impact when other criteria have failed. Human tolerance has been defined by the Viscous response, [VC], a time function generated by the instantaneous product of velocity of deformation [V(t)] and amount of compression [C(t)] of the body. [VC]max = 1.0 m/s corresponds experimentally to a 25% chance of sustaining severe thoracic injury (AIS ≥ 4) in a blunt frontal impact. A similar level of risk for critical abdominal injury (AIS ≥ 5) in a blunt frontal impact is [VC]max = 1.2 m/s. However, human tolerance is defined more completely by the probability function of injury risk versus [VC]max. The Viscous response can be evaluated in the Hybrid III anthropomorphic dummy by a straightforward analysis of the chest deflection data.

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 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.

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.