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- López-Valdés, F. J., et al.
(författare)
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Analysis of occupant kinematics and dynamics in nearside oblique impacts
- 2016
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Ingår i: Traffic Injury Prevention. - : Taylor & Francis. - 1538-9588 .- 1538-957X. ; 17, s. 86-92
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The objective of this article is to analyze the kinematics and dynamics of restrained postmortem human surrogates (PMHS) exposed to a nearside oblique impact and the injuries that were found after the tests.Methods: Three male PMHS of similar age (64 4years) and anthropometry (weight: 61 9.6kg; stature: 172 +/- 2.7cm) were exposed to a 30 degrees nearside oblique impact at 34km/h. The test fixture approximated the seating position of a front seat occupant. A rigid seat was designed to match the pelvic displacement in a vehicle seat. Surrogates were restrained by a 3-point seat belt consisting of a 2kN pretensioner (PT), 4.5kN force-limiting shoulder belt, and a 3.5kN PT lap belt. The shoulder belt PT was not fired in one of the tests. Trajectories of the head, shoulder, and hip joint (bilaterally) were recorded at 1,000Hz by a 3D motion capture system. The 3D acceleration and angular rate of the head, T1, and pelvis, and the 3D acceleration of selected spinal locations was measured at 10,000Hz. Seat belt load cells measured the belt tension at 4 locations. PMHS donation and handling were performed with the approval of the relevant regional ethics review board.Results: Activation of the shoulder PT reduced substantially the peak forward excursion of the head but did not influence the lateral displacement of the head center of gravity (CG). In all 3 subjects, the lateral excursion of the head CG (291.1, 290, 292.1mm) was greater than the forward displacement (271.4, 216.7, 171.5mm). The hip joint excursion of the PMHS that was not exposed to the shoulder PT seat belt was twice the magnitude observed for the other 2 subjects. The 3 PMHS sustained clavicle fractures on the shoulder loaded by the seat belt and 2 of them were diagnosed atlantoaxial subluxation in the radiologist examination. Avulsion fractures of the right lamina of T1, T2, T3, and T4 were found when the PT was not used. The 3 PMHS received multiple fractures spread over both aspects of the rib cage and involving the posterior aspect of it.Conclusion: In this study of nearside oblique impact loading, the PMHS exhibited kinematics characterized by reduced torso pitching and increased lateral head excursion as compared to previous frontal impact results. These kinematics resulted in potential cervical and thoracic spinal injuries and in complete, displaced fractures of the lateral and posterior aspects of the rib cage. Though this is a limited number of subjects, it shows the necessity of further understanding of the kinematics of occupants exposed to this loading mode.
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| 2. |
- Pipkorn, Bengt, 1963, et al.
(författare)
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Study of the Kinematics of the THOR dummy in Nearside Oblique Impacts
- 2016
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Ingår i: 2016 IRCOBI Conference Proceedings - International Research Council on the Biomechanics of Injury.
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Konferensbidrag (refereegranskat)abstract
- Oblique and small-overlap crashes are the second most common frontal crash type leading to fatal outcome. This study discusses a simplified test rig suitable to analyse the performance of the THOR dummy in oblique impacts. Secondly, this paper compares the kinematics and dynamics of the THOR dummy under the loading of two types of seat belts. The generic test rig was based on the Gold Standard fixture. By means of mathematical simulations with the THOR dummy model different seat designs were evaluated so that the dummy kinematics could approximate those observed in real vehicles. Thereafter two different three-point seat belt systems were evaluated via physical and computer-modelled sled tests: a pretensioned (shoulder retractor and lap) force-limiting seat belt (reference seat belt) and an innovative belt in which the shoulder and the lap bands were split (split buckle). The study shows that THOR pelvic displacement was significantly reduced with the modified seat compared to the originally flat Gold Standard seat in a more realistic manner. The THOR dummy was able to discriminate between the two seat belt systems and the results suggest that the split buckle restraint has the potential to achieve significant injury reducing benefits in the oblique loading condition.
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| 3. |
- Piqueras-Lorente, Ana, et al.
(författare)
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Kinematic assessment of subject personification of human body models (THUMS)
- 2018
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Ingår i: Conference proceedings International Research Council on the Biomechanics of Injury, IRCOBI. - 2235-3151. ; 2018-September, s. 191-206
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Konferensbidrag (refereegranskat)abstract
- The goal of this study was to quantify the effect of improving the geometry of a human body model on the accuracy of the predicted kinematics for 4 post-mortem human subject sled tests. Three modifications to the computational human body model THUMS were carried out to evaluate if subject personification can increase the agreement between predicted and measured kinematics of post-mortem human subjects in full frontal and nearside oblique impacts. The modifications consisted of: adjusting the human body model mass to the actual subject mass, morphing it to the actual anthropometry of each subject and finally adjustment of the model initial position to the measured position in selected post-mortem human subject tests. A quantitative assessment of the agreement between predicted and measured response was carried out by means of CORA analysis by comparing the displacement of selected anatomical landmarks (head CoG, T1 and T8 vertebre and H-Point). For all three scenarios, the more similar the human body model was to the anthropometry and posture of the sled tested post-mortem human subject, the more similar the predictions were to the measured responses of the post-mortem human subject, resulting in higher CORA score.
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