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- Liu, Xuejun, 1971, et al.
(författare)
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A study of influence of vehicle speed and front structure on pedestrian impact responses using mathematical models
- 2002
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Ingår i: Traffic Injury Prevention. - 1538-957X .- 1538-9588. ; 3:1, s. 31-42
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Tidskriftsartikel (refereegranskat)abstract
- A validated pedestrian multibody model was used to investigate the influences of impact speed andvehicle front structure on the pedestrian dynamic responses in vehicle collisions. To predict theinjury risks of pedestrians at different impact speeds, the injury-related parameters concerninghead, chest and lower extremity areas were calculated from mathematical simulations. Four vehicletypes including large and compact passenger cars, minivans and light trucks were simulatedaccording to their frequency of involvement in real world accidents. The influences of variousvehicle front shape and compliance parameters were analyzed.Based on the results from the parametric study, the possible benefits from speed control in urbanarea were assessed, and a feasible speed limit was proposed to reduce the risks of pedestrianinjuries. Moreover, the possible countermeasures on basis of vehicle front design to mitigate theinjury severity of the pedestrians were discussed.
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| 2. |
- Yang, Jikuang, 1948, et al.
(författare)
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A Human- 3D Mathematical Model for Simulation of Car-Pedestrian Impacts
- 2000
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Ingår i: Traffic Injury Prevention. - 1538-957X .- 1538-9588. ; 2:2, s. 131-149
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Tidskriftsartikel (refereegranskat)abstract
- A 3D mathematical model of the human body was developed to simulate responses ofpedestrians in car impacts. The model consists of fifteen body segments connected by fourteenjoints, including two human-like knee joints and two breakable-leg segments. The anthro-pometrical data for the model were generated by theGEBODprogram, and characteristics ofthe body segments and the joints were defined based on available biomechanical data.The validity of the model was evaluated against full-scale impact tests with pedestriansubstitutes and an experimental car in terms of the kinematics of the pedestrian substitute,bumper impact forces, accelerations of the body segments, and failure description fromanatomical investigations of the pedestrian substitutes.The sensitivity of the model to input variables was studied at impact speeds of 15 and40 km/h with the following car-front parameters: bumper height, bumper stiffness, bumper-lead distance, height of hood edge, and hood-edge stiffness. The validated model demonstratedits capability in simulations of car±pedestrian impacts for the assessment of responses ofpedestrians, prediction of risks of pedestrian injuries and for the development of safetycountermeasures.
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| 3. |
- Boström, Ola, 1963, et al.
(författare)
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Comparison of car seats in low speed rear-end impacts using the BioRID dummy and the new neck injury criterion (NIC).
- 2000
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Ingår i: Accident Analysis and Prevention. ; 32:2, s. 321-328
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Tidskriftsartikel (refereegranskat)abstract
- Long-term whiplash associated disorders (WAD) 1-3 sustained in low velocity rear-end impacts is the most common disability injury in Sweden. Therefore, to determine neck injury mechanisms and develop methods to measure neck-injury related parameters are of importance for current crash-safety research. A new neck injury criterion (NIC) has previously been proposed and evaluated by means of dummy, human and mathematical rear-impact simulations. So far, the criterion appears to be sensitive to the major car and collision related risk factors for injuries with long-term consequences. To further evaluate the applicability of NIC, four seats were tested according to a recently proposed sled-test procedure. 'Good' as well as 'bad' seats were chosen on the basis of a recently presented disability risk ranking list. The dummy used in the current tests was the Biofidelic Rear Impact Dummy (BioRID). The results of this study showed that NICmax values were generally related to the real-world risk of long-term WAD 1-3. Furthermore, these results suggested that NICmax calculated from sled tests using the BioRID dummy can be used for evaluating the neck injury risk of different car seats.
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| 7. |
- Svensson, Mats, 1960, et al.
(författare)
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Neck injuries in car collisions--a review covering a possible injury mechanism and the development of a new rear-impact dummy
- 2000
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Ingår i: Accident Analysis and Prevention. - 0001-4575. ; 32:2, s. 167-75
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Tidskriftsartikel (refereegranskat)abstract
- A review of a few Swedish research projects on soft tissue neck injuries in car collisions is presented together with some new results. Efforts to determine neck injury mechanisms was based on a hypothesis stating that injuries to the nerve root region in the cervical spine are a result of transient pressure gradients in the spinal canal during rapid neck bending. In experimental neck trauma research on animals, pressure gradients were observed and indications of nerve cell membrane dysfunction were found in the cervical spinal ganglia. The experiments covered neck extension, flexion and lateral bending. A theoretical model in which fluid flow was predicted to cause the transient pressure gradients was developed and a neck injury criterion based on Navier-Stokes Equations was applied on the flow model. The theory behind the Neck Injury Criterion indicates that the neck injury occurs early on in the rearward motion of the head relative to the torso in a rear-end collision. Thus the relative horizontal acceleration and velocity between the head and the torso should be restricted during the early head-neck motion to avoid neck injury. A Bio-fidelic Rear Impact Dummy (BioRID) was developed in several steps and validated against volunteer test results. The new dummy was partly based on the Hybrid III dummy. It had a new articulated spine with curvature and range of motion resembling that of a human being. A new crash dummy and a neck injury criterion will be very important components in a future rear-impact crash test procedure.
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