scholarly journals Realistic Reference for Evaluation of Vehicle Safety Focusing on Pedestrian Head Protection Observed From Kinematic Reconstruction of Real-World Collisions

2021 ◽  
Vol 9 ◽  
Author(s):  
Guibing Li ◽  
Jinming Liu ◽  
Kui Li ◽  
Hui Zhao ◽  
Liangliang Shi ◽  
...  
Keyword(s):  
Head Injury ◽  
Impact Velocity ◽  
Real World ◽  
Contact Time ◽  
Injury Risk ◽  
Safety Performance ◽  
Contact Boundary ◽  
Vehicle Safety ◽  
Pedestrian Protection ◽  
Vehicle Impact

Head-to-vehicle contact boundary condition and criteria and corresponding thresholds of head injuries are crucial in evaluation of vehicle safety performance for pedestrian protection, which need a constantly updated understanding of pedestrian head kinematic response and injury risk in real-world collisions. Thus, the purpose of the current study is to investigate the characteristics of pedestrian head-to-vehicle contact boundary condition and pedestrian AIS3+ (Abbreviated Injury Scale) head injury risk as functions of kinematic-based criteria, including HIC (Head Injury Criterion), HIP (Head Impact Power), GAMBIT (Generalized Acceleration Model for Brain Injury Threshold), RIC (Rotational Injury Criterion), and BrIC (Brain Injury Criteria), in real-world collisions. To achieve this, 57 vehicle-to-pedestrian collision cases were employed, and a multi-body modeling approach was applied to reconstruct pedestrian kinematics in these real-world collisions. The results show that head-to-windscreen contacts are dominant in pedestrian collisions of the analysis sample and that head WAD (Wrap Around Distance) floats from 1.5 to 2.3 m, with a mean value of 1.84 m; 80% of cases have a head linear contact velocity below 45 km/h or an angular contact velocity less than 40 rad/s; pedestrian head linear contact velocity is on average 83 ± 23% of the vehicle impact velocity, while the head angular contact velocity (in rad/s) is on average 75 ± 25% of the vehicle impact velocity in km/h; 77% of cases have a head contact time in the range 50–140 ms, and negative and positive linear correlations are observed for the relationships between pedestrian head contact time and WAD/height ratio and vehicle impact velocity, respectively; 70% of cases have a head contact angle floating from 40° to 70°, with an average value of 53°; the pedestrian head contact angles on windscreens (average = 48°) are significantly lower than those on bonnets (average = 60°); the predicted thresholds of HIC, HIP, GAMBIT, RIC, BrIC2011, and BrIC2013 for a 50% probability of AIS3+ head injury risk are 1,300, 60 kW, 0.74, 1,470 × 104, 0.56, and 0.57, respectively. The findings of the current work could provide realistic reference for evaluation of vehicle safety performance focusing on pedestrian protection.

Effects of vehicle front-end safety countermeasures on pedestrian head injury risk during ground impact

2019 ◽  
Vol 233 (14) ◽  
pp. 3588-3599 ◽  
Author(s):  
Liangliang Shi ◽  
Yong Han ◽  
Hongwu Huang ◽  
Wei He ◽  
Fang Wang ◽  
...  
Keyword(s):  
Injury Risk ◽  
Rotation Angle ◽  
Head Injuries ◽  
Leading Edge ◽  
Vehicle Safety ◽  
Secondary Impact ◽  
Front End ◽  
Vehicle Impact ◽  
Safety Countermeasures ◽  
Primary Impact

Pedestrian safety countermeasures such as pop-up bonnets and exterior pedestrian airbags have been shown to decrease the pedestrian injury risk caused by vehicle impacts (primary impact). However, it is still unknown whether these devices could prevent or mitigate pedestrian injuries resulting from ground impacts (secondary impact). In order to understand how the vehicle safety countermeasures prevent pedestrian head injuries caused by primary and secondary impacts, a total of 252 vehicle-to-pedestrian impact simulations were conducted using the MADYMO code. The simulations accounted for three types of vehicle configurations (a baseline vehicle and vehicles with the two aforementioned vehicle safety countermeasures) along with five front-end structural parameters at three vehicle impact velocities (30, 40, and 50 km/h). The simulation results show that the bonnet leading edge height was the most sensitive parameter affecting the head-to-vehicle impact location and that caused different head injuries resulting from the local stiffness in the location impacted. Moreover, the bonnet leading edge height was the leading governing factor on the pedestrian rotation angle in the secondary impact. The vehicle equipped with a pop-up bonnet and an external airbag could cause a larger pedestrian rotation angle at 30 km/h than that in the other two vehicle types, but conversely could cause a smaller pedestrian rotation angle at 40 and 50 km/h. Also, the vehicle equipped with pop-up bonnet and external airbag systems could lead a higher pedestrian flight altitude than that of the baseline type. A vehicle equipped with a pop-up bonnet and external airbag systems provide improved protection for the pedestrian’s head in the primary impact, but may not prevent the injury risk and/or even cause more severe injuries in secondary impacts.

scholarly journals INVESTIGATION ON RISK PREDICTION OF PEDESTRIAN HEAD INJURY BY REAL-WORLD ACCIDENTS

Transport ◽  
2019 ◽  
Vol 34 (3) ◽  
pp. 394-403
Author(s):  
Fan Li ◽  
Honggeng Li ◽  
Fuhao Mo ◽  
Sen Xiao ◽  
Zhi Xiao
Keyword(s):  
Head Injury ◽  
Brain Tissue ◽  
Real World ◽  
Injury Risk ◽  
Brain Injuries ◽  
Physical Parameters ◽  
Kinematic Parameters ◽  
Injury Criteria ◽  
Head Injury Criteria ◽  
Pedestrian Accidents

Head injury is the most common and fatal injury in car-pedestrian accidents. Due to the lack of human test data, real-world accident data is useful for the research on the mechanism and tolerance of head injuries. The objective of the present work is to investigate pedestrian head-brain injuries through real car-pedestrian accidents and evaluate the existed injury criteria. Seven car-to-pedestrian accidents in China were selected from the IVAC (Investigation of Vehicle Accident in Changsha) database. Accident reconstructions using multi-body models were conducted to determine the kinematic parameters associated with the injury and were used to measure head injury criteria. Kinematic parameters were input into a finite element model to run simulations on the head-brain and car interface to determine levels of brain tissue stress, strain, and brain tissue injury criteria. A binary logistic regression model was used to determine the probability of head injury risk associated with AIS3+ injuries (Abbreviated Injury Scale). The results showed that head injury criteria using kinematic parameters can effectively predict injury risk of a pedestrians’ head skull. Regarding brain injuries, physical parameters like coup/countercoup pressure are more effective predictors. The results of this study can be used as the background knowledge for pedestrian friendly car design.

Effects of Vehicle Impact Velocity, Vehicle Front-End Shapes on Pedestrian Injury Risk

2012 ◽  
Vol 13 (5) ◽  
pp. 507-518 ◽  
Author(s):  
Yong Han ◽  
Jikuang Yang ◽  
Koji Mizuno ◽  
Yasuhiro Matsui
Keyword(s):  
Impact Velocity ◽  
Injury Risk ◽  
Front End ◽  
Pedestrian Injury ◽  
Vehicle Impact

Development of head injury risk functions based on real-world accident reconstruction

2013 ◽  
Vol 19 (2) ◽  
pp. 105-114 ◽  
Author(s):  
Yong Peng ◽  
Jikuang Yang ◽  
Caroline Deck ◽  
Dietmar Otte ◽  
Remy Willinger
Keyword(s):  
Head Injury ◽  
Real World ◽  
Injury Risk ◽  
Accident Reconstruction ◽  
Risk Functions

scholarly journals A Study on Influence of Minivan Front-End Design and Impact Velocity on Pedestrian Thorax Kinematics and Injury Risk

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Fang Wang ◽  
Chao Yu ◽  
Guibing Li ◽  
Yong Han ◽  
Bingyu Wang ◽  
...  
Keyword(s):  
Impact Velocity ◽  
Injury Risk ◽  
Research Work ◽  
Thoracic Injury ◽  
Chinese Market ◽  
Computational Biomechanics ◽  
Front End ◽  
Vehicle Impact ◽  
Pedestrian Impact ◽  
The Impact

Thoracic injuries occur frequently in minivan-to-pedestrian impact accidents and can cause substantial fatalities. The present research work investigates the human thoracic responses and injury risks in minivan-to-pedestrian impacts, when changing the minivan front-end design and the impact velocity, by using computational biomechanics model. We employed three typical types of minivan model of different front-end designs that are quite popular in Chinese market and considered four impact velocities (20, 30, 40, and 50 km/h). The contact time of car to thorax region (CTCTR), thorax impact velocity, chest deformation, and thoracic injury risks were extracted for the investigation. The results indicate that the predicted pedestrian kinematics, injury responses, and thoracic injury risks are strongly affected by the variation of the minivan front-end design and impact velocity. The pedestrian thoracic injury risks increase with the increasing vehicle impact velocity. It is also revealed that the application of the extra front bumper is beneficial for reducing the thoracic injury risk, and a relatively flatter minivan front-end design gives rise to a higher thoracic injury risk. This study is expected to be served as theoretical references for pedestrian protection design of minivans.

scholarly journals Is Acceleration a Valid Proxy for Injury Risk in Minimal Damage Traffic Crashes? A Comparative Review of Volunteer, ADL and Real-World Studies

2021 ◽  
Vol 18 (6) ◽  
pp. 2901
Author(s):  
Paul S. Nolet ◽  
Larry Nordhoff ◽  
Vicki L. Kristman ◽  
Arthur C. Croft ◽  
Maurice P. Zeegers ◽  
...  
Keyword(s):  
Real World ◽  
Injury Risk ◽  
Angular Acceleration ◽  
Traffic Crashes ◽  
Rear Impact ◽  
Comparative Review ◽  
Minimal Damage ◽  
Injury Causation ◽  
Crash Tests ◽  
Biomechanical Approach

Injury claims associated with minimal damage rear impact traffic crashes are often defended using a “biomechanical approach,” in which the occupant forces of the crash are compared to the forces of activities of daily living (ADLs), resulting in the conclusion that the risk of injury from the crash is the same as for ADLs. The purpose of the present investigation is to evaluate the scientific validity of the central operating premise of the biomechanical approach to injury causation; that occupant acceleration is a scientifically valid proxy for injury risk. Data were abstracted, pooled, and compared from three categories of published literature: (1) volunteer rear impact crash testing studies, (2) ADL studies, and (3) observational studies of real-world rear impacts. We compared the occupant accelerations of minimal or no damage (i.e., 3 to 11 kph speed change or “delta V”) rear impact crash tests to the accelerations described in 6 of the most commonly reported ADLs in the reviewed studies. As a final step, the injury risk observed in real world crashes was compared to the results of the pooled crash test and ADL analyses, controlling for delta V. The results of the analyses indicated that average peak linear and angular acceleration forces observed at the head during rear impact crash tests were typically at least several times greater than average forces observed during ADLs. In contrast, the injury risk of real-world minimal damage rear impact crashes was estimated to be at least 2000 times greater than for any ADL. The results of our analysis indicate that the principle underlying the biomechanical injury causation approach, that occupant acceleration is a proxy for injury risk, is scientifically invalid. The biomechanical approach to injury causation in minimal damage crashes invariably results in the vast underestimation of the actual risk of such crashes, and should be discontinued as it is a scientifically invalid practice.

Morphomic Analysis of Thoracic Injury Risk in Live Subjects From Real World Motor Vehicle Crashes

2014 ◽  
Vol 186 (2) ◽  
pp. 659-660
Author(s):  
E.T. Chang ◽  
S. Holcombe ◽  
C. Kohoyda-Inglis ◽  
J.B. MacWilliams ◽  
C. Parenteau ◽  
...  
Keyword(s):  
Real World ◽  
Injury Risk ◽  
Motor Vehicle ◽  
Motor Vehicle Crashes ◽  
Thoracic Injury ◽  
Vehicle Crashes

Effects of Vehicle Impact Velocity on Cyclist Injuries and Kinematics for Rear Impacts

2019 ◽  
pp. 281-288
Author(s):  
Ovidiu Andrei Condrea ◽  
Anghel Chiru ◽  
George Radu Togănel ◽  
Daniel Dragos Trusca
Keyword(s):  
Impact Velocity ◽  
Vehicle Impact ◽  
Rear Impacts

scholarly journals The assessment of pedestrian`s head injury risk at the contact with the vehicle`s hood

2019 ◽  
Vol Volume XXIX (XIX), 2019/3 (3) ◽  
Author(s):  
H Beles ◽  
B A Tolea ◽  
G F Crisan ◽  
C A Dogar ◽  
V V Ciotachiev
Keyword(s):  
Head Injury ◽  
Injury Risk

scholarly journals Evaluation of Head Injury Criteria for Injury Prediction Effectiveness: Computational Reconstruction of Real-World Vulnerable Road User Impact Accidents

2021 ◽  
Vol 9 ◽  
Author(s):  
Fang Wang ◽  
Zhen Wang ◽  
Lin Hu ◽  
Hongzhen Xu ◽  
Chao Yu ◽  
...  
Keyword(s):  
Head Injury ◽  
Real World ◽  
Head Injuries ◽  
Axonal Injury ◽  
Diffuse Axonal Injury ◽  
Road User ◽  
Injury Criteria ◽  
Brain Deformation ◽  
Vulnerable Road User ◽  
Head Injury Criteria

This study evaluates the effectiveness of various widely used head injury criteria (HICs) in predicting vulnerable road user (VRU) head injuries due to road traffic accidents. Thirty-one real-world car-to-VRU impact accident cases with detailed head injury records were collected and replicated through the computational biomechanics method; head injuries observed in the analyzed accidents were reconstructed by using a finite element (FE)-multibody (MB) coupled pedestrian model [including the Total Human Model for Safety (THUMS) head–neck FE model and the remaining body segments of TNO MB pedestrian model], which was developed and validated in our previous study. Various typical HICs were used to predict head injuries in all accident cases. Pearson’s correlation coefficient analysis method was adopted to investigate the correlation between head kinematics-based injury criteria and the actual head injury of VRU; the effectiveness of brain deformation-based injury criteria in predicting typical brain injuries [such as diffuse axonal injury diffuse axonal injury (DAI) and contusion] was assessed by using head injury risk curves reported in the literature. Results showed that for head kinematics-based injury criteria, the most widely used HICs and head impact power (HIP) can accurately and effectively predict head injury, whereas for brain deformation-based injury criteria, the maximum principal strain (MPS) behaves better than cumulative strain damage measure (CSDM0.15 and CSDM0.25) in predicting the possibility of DAI. In comparison with the dilatation damage measure (DDM), MPS seems to better predict the risk of brain contusion.

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