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Two post-mortem human subjects were subjected to dynamic, non-injurious (up to 20% chest deflection) anterior shoulder belt loading at 0.5 m/s and 0.9 m/s loading rates. The human surrogates were mounted to a stationary apparatus that supported the spine and shoulder in a configuration comparable to that achieved in a 48 km/h sled test at the time of maximum chest deformation. A hydraulically driven shoulder belt was used to load the anterior thorax which was instrumented with a load cell for measuring reaction force and uniaxial strain gages at the 4th and 8th ribs. In addition, the deformation of the chest was measured using a 16- camera Vicon 3D motion capture system. In order to investigate the chest deformation pattern and ribcage loading in greater detail, a human finite element (FE) model of the thorax was used to simulate the tests.

Previous full-scale pedestrian impact experiments using post-mortem human surrogates (PMHS) and sled-mounted vehicle bucks have shown that vehicle shape relative to pedestrian anthropometry may influence pedestrian kinematics and injury mechanisms. While a parametric study examining these factors could elucidate the complex relationships that govern pedestrian kinematics, it would be impractical with PMHS tests due to the relative expense involved in performing numerous experiments on subjects with varying anthropometry. Finite element (FE) modeling represents a more feasible approach since numerous experiments can be conducted with a fraction of the expense. However, there have been no studies to date depicting kinematic validation of a human pedestrian FE model in full-scale collisions using different vehicle and pedestrian geometries. Therefore, this study used an FE model of the Polar-II pedestrian dummy that was previously validated against full-scale test data.

The goal of this study was to develop and validate a finite element (FE) model of the Polar-II pedestrian dummy. An upper body model consisting of the head, neck, shoulder, thorax, and abdomen was coupled with a previously validated model of the lower limb The viscoelastic material properties of the dummy components were determined from dynamic compression tests of shoulder urethane, shoulder rubber and abdominal foam. For validation of the entire upper body, the model was compared with NHTSA response requirements for their advanced frontal dummy (Thor) including head and neck pendulum tests as well as ribcage and abdominal impact tests. In addition, the Polar-II full body FE model was subjected to simulated vehicle-pedestrian impacts that recreated published experiments. Simulated head and pelvis accelerations as well as upper body trajectories reasonably reproduced the experiment.

Previous studies utilizing the Polar-II pedestrian dummy have suggested the need for a more biofidelic pelvis design in order to improve the overall dummy response kinematics. The current Polar-II dummy pelvis is a rigid steel structure. A preliminary version of a modified deformable pelvis equipped with sensors for measuring internal deflection and load has been designed. The goal of this study was to assess the biofidelity of these two pelves in full-scale tests with the Polar-II dummy that mimic lateral pelvic impact tests on PMHS (post-mortem human subjects) reported in the literature. The force - time, deflection - time, and force - deflection histories were compared to new PMHS response corridors determined using a normalization technique. In all tests with both pelves, the initial response (i.e., the first 3 ms to 5 ms following initial dummy - impactor contact) appeared to be totally determined by the mechanical behavior of the flesh.

Child restraint head padding is designed for the child's comfort under normal use. Under vehicle crash conditions, however, the padding in a rear facing child restraint may not be designed to sufficiently absorb impact energy. The objective of this paper is to evaluate the effects of various head padding conditions in rear facing child restraints in frontal impacts. Five sled tests were performed to measure the response of a CRABI 12 month dummy to different padding conditions in a rear facing child restraint. Static loading tests were performed on the padding materials. Results show that using padding of low stiffness increases head acceleration and HIC15 values.

The structural properties of the four major human knee ligaments were investigated at different loading rates. Bone-ligament-bone specimens of the medial and lateral collateral ligaments and the anterior and posterior cruciate ligaments, obtained from post-mortem human donors, were tested in knee distraction loading in displacement control. All ligaments were tested in the anatomical position corresponding to a fully extended knee. The rate dependence of the structural response of the knee ligaments was investigated by applying loading-unloading cycles at a range of distraction rates. Ramps to failure were applied at knee distraction rates of 0.016 mm/s, 1.6 mm/s, or 1,600 mm/s. Averages and corridors were constructed for the force response and the failure point of the different ligaments and loading rates. The structural response of the knee ligaments was found to depend on the deformation rate, being both stiffer and more linear at high loading rates.

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.