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Han Y, Wu H, Pan D, Su L, Shi L, Wang F. Development of a head-weighted injury criterion for evaluation of multiple types of AIS 4+ injuries for vulnerable road users. J Biomech 2024; 165:112024. [PMID: 38412622 DOI: 10.1016/j.jbiomech.2024.112024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 02/18/2024] [Accepted: 02/22/2024] [Indexed: 02/29/2024]
Abstract
Vulnerable Road users (VRUs) often suffer multiple fatal head injury types simultaneously in road accidents. In this study, a head-weighted injury criterion (HWIC4) was proposed for assessing the risk of head AIS 4+ injuries considering multiple injury types. Firstly, the kinematic characteristics of VRUs in the 50 in-depth accidents were reconstructed by using multi-body system models, and head injuries were reconstructed using eight head kinematic-based injury criteria and eight brain tissue injury criteria via the THUMS (Ver. 4.0.2) head finite element model. The predictive capability of each injury criterion to predict head AIS 4+ injuries was assessed and four better predictors (HIC15, angular acceleration, coup pressure, and maximum principal strain) were selected. The different head injury types and the weighting parameters for each injury type were taken into account in the development of HWIC4. Finally, the effectiveness and evaluation of HWIC4 for head AIS 4+ injury was validated based on the area under of receiver operating characteristic (AUROC) curve and reconstruction results from 10 additional selected accident cases. The results showed that HWIC4 has a good predictive capability for head AIS 4+ injuries with an AUROC of 0.983, which means that HWIC4 is superior and more reliable than a single head injury criterion. This knowledge further improves the capability of head injury criteria to predict head AIS 4+ injuries.
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Affiliation(s)
- Yong Han
- School of Mechanical and Automotive Engineering, Xiamen University of Technology, Xiamen, China; Fujian Key Laboratory of Advanced Design and Manufacture for Coach, Xiamen, China.
| | - He Wu
- Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen, China
| | - Di Pan
- School of Mechanical and Automotive Engineering, Xiamen University of Technology, Xiamen, China; Fujian Key Laboratory of Advanced Design and Manufacture for Coach, Xiamen, China
| | - Liang Su
- Engineering Research Institute of Xiamen Jinlong United Automobile Industry Co., Ltd., Xiamen, China
| | - Liangliang Shi
- State Key Laboratory of Vehicle NVH and Safety Technology, China Automotive Engineering Research Institute Co., Ltd., Chongqing, China
| | - Fang Wang
- School of Automotive and Mechanical Engineering, Changsha University of Science and Technology, Changsha, China
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Pérez-Zuriaga AM, Dols J, Nespereira M, García A, Sajurjo-de-No A. Analysis of the consequences of car to micromobility user side impact crashes. JOURNAL OF SAFETY RESEARCH 2023; 87:168-175. [PMID: 38081692 DOI: 10.1016/j.jsr.2023.09.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 07/28/2023] [Accepted: 09/18/2023] [Indexed: 12/18/2023]
Abstract
INTRODUCTION The strong rise in modes of travel commonly referred to as micromobility has changed the mobility patterns and lifestyles in cities worldwide, especially after the COVID-19 pandemic. It has led to a significant increase in the number of crashes involving these types of vehicles, especially bicycles and stand-up e-scooters. The risk of crashes is higher at intersections where motor-vehicles perform a turning maneuver crossing a bike lane. METHOD The consequences of a passenger car-to-micromobility vehicle side-impact crashes, considering both bicycle and e-scooter, were studied based on the results of the simulation of several scenarios with PC-Crash software. Two injury criteria were applied: Head Injury Criterion (HIC15) and 3 ms chest acceleration criterion. RESULTS When motor-vehicle speed is lower than 50 km/h, the 3 ms chest acceleration never exceeds the 60 g threshold. However, at 50 km/h, it is close to 50 g in the case of e-scooter rides. At this speed, HIC15 is considerably greater than 1000, both for bicycles and for e-scooters, and the safety margin of 700 is exceeded at 45 km/h for e-scooters. CONCLUSIONS In case of motor vehicle-to-micromobility vehicle side-impact crash, riding a bicycle is safer than riding an e-scooter since the observed HIC15 experienced by the cyclists is lower than that experienced by the e-scooter rider when motor vehicle speed is greater than 30 km/h. PRACTICAL APPLICATIONS To reduce micromobility users injury risk at intersections, motor vehicle speed limit should be equal or lower than 40 km/h. At this impact speed, the activation of hood or bumper airbags could be justified.
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Affiliation(s)
- Ana María Pérez-Zuriaga
- Highway Engineering Research Group (HERG), Universitat Politècnica de València, Camino de Vera, s/n, 46022 Valencia, Spain
| | - Juan Dols
- Institute of Design and Manufacturing, Universitat Politècnica de València, Camino de Vera, s/n, 46022 Valencia, Spain
| | - Martín Nespereira
- Institute of Design and Manufacturing, Universitat Politècnica de València, Camino de Vera, s/n, 46022 Valencia, Spain
| | - Alfredo García
- Highway Engineering Research Group (HERG), Universitat Politècnica de València, Camino de Vera, s/n, 46022 Valencia, Spain
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Tan P, Huang Y, Tang J, Long Y, Liu Y, Zhou Q. Kinematic responses of child as second rider of electric-two-wheelers under lateral impact with vehicle. ACCIDENT; ANALYSIS AND PREVENTION 2023; 192:107258. [PMID: 37611508 DOI: 10.1016/j.aap.2023.107258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 07/09/2023] [Accepted: 08/02/2023] [Indexed: 08/25/2023]
Abstract
Electric-two-wheeler (E2W) related accidents have become a major safety concern on road due to the growing prevalence and the high casualty rate. Most existing studies focus on drivers of the E2W, while ignore the second rider (usually a child) as passenger. This study aims at investigating the kinematic response of the child rider upon vehicle impact and analyzing how motion patterns are influenced by the geometric parameters of the vehicle and E2W. A computational framework was established for the intended task. We modeled the E2W-rider system in Madymo, including an E2W with parametric geometry and two riders, one adult and one child respectively. This study focuses on lateral impact in terms of the accident scenarios, as the case dominates in the field data reports. Vehicle types, seating height of the E2W and sitting position of the child rider were considered as variables in the simulation matrix. Results show that the relative height between child's sitting and vehicle hood front-edge, and the sitting position (back-seated or front-seated) are two main influencing parameters on kinematic responses of child rider. The child rider tends to bounce higher on hood upon impact when sitting above the hood front-edge, while might be laterally pushed away by the car-front when sitting below the hood front-edge. Meanwhile, back-seated child rider is more likely to rise higher and rotate faster upon impact compared to a front-seated one. These findings may guide safe riding and safety countermeasure development for child riders of E2W.
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Affiliation(s)
- Puyuan Tan
- State Key Lab of Automotive Safety and Energy, School of Vehicle and Mobility, Tsinghua University, Beijing 100084, China
| | - Yuan Huang
- State Key Lab of Automotive Safety and Energy, School of Vehicle and Mobility, Tsinghua University, Beijing 100084, China
| | - Jisi Tang
- State Key Lab of Automotive Safety and Energy, School of Vehicle and Mobility, Tsinghua University, Beijing 100084, China
| | - Yongcheng Long
- China Automotive Engineering Research Institute Co., Ltd, Chongqing 401122, China
| | - Yu Liu
- China Automotive Engineering Research Institute Co., Ltd, Chongqing 401122, China
| | - Qing Zhou
- State Key Lab of Automotive Safety and Energy, School of Vehicle and Mobility, Tsinghua University, Beijing 100084, China.
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Han Y, He Y, Pan D, Lin L, Chen Y, Feng H. Effect of different helmets against ground impact based on the in-depth reconstruction of electric two-wheeler accidents. Comput Methods Biomech Biomed Engin 2023; 26:460-483. [PMID: 35483035 DOI: 10.1080/10255842.2022.2066974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Skull fracture and brain injury are frequent head injuries in electric two-wheeler (ETW) accidents, and the type of helmet and impact conditions affect the effectiveness of the helmet in protecting the rider's head. The purpose of this study was to conduct in-depth reconstructions of rider's head-to-ground impacts in ten ETW accidents by using a multi-body system combined with a finite element approach and to evaluate the effect of two typical full-face helmets (FFH) and one half-coverage helmet (HCH) through head accelerations and intracranial biomechanics injury metrics in ground impacts. The results showed that all three helmets reduced the risk of skull fracture in most cases, however, FFH performed better due to its wider protection area. In addition, three helmets showed varying degrees of overall reduction in measuring all indicators of brain injury. Although the effectiveness of the helmets on angular acceleration was largely influenced by the angle and location of impact, it was certain that wearing an FFH was more likely to reduce rotational head movements than an HCH, and that the FFH also offered the better advantage in reducing diffuse axonal injury (DAI) risk due to its better resistance to ejection in a crash.
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Affiliation(s)
- Yong Han
- Xiamen University of Technology, Xiamen, China
| | - Yong He
- Xiamen University of Technology, Xiamen, China
| | - Di Pan
- Xiamen University, Xiamen, China
| | - Liya Lin
- Xiamen University of Technology, Xiamen, China
| | - Yisheng Chen
- Xiamen YUQUAN Composite Technology Co., Ltd, Xiamen, China
| | - Hao Feng
- Key Laboratory of Forensic Science, Ministry of Justice, China (Academy of Forensic Science), Shanghai, China.,The Key Laboratory of Road and Traffic Engineering, Ministry of Education, Tongji University, Shanghai, China
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Shen Z, Ji W, Yu S, Cheng G, Yuan Q, Han Z, Liu H, Yang T. Mapping the knowledge of traffic collision Reconstruction: A scientometric analysis in CiteSpace, VOSviewer, and SciMAT. Sci Justice 2023; 63:19-37. [PMID: 36631179 DOI: 10.1016/j.scijus.2022.10.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 09/26/2022] [Accepted: 10/23/2022] [Indexed: 11/13/2022]
Abstract
Traffic collisions are incidents with high fatality rate which generate billions of US dollars of loss worldwide each year. Post-collision scene reconstruction, which involves knowledge of multiple disciplines, is an important approach to restore the traffic collision and infer the cause of it. This paper uses software CiteSpace, VOSviewer, and SciMAT to conduct a visualization study of knowledge mapping on the literature of traffic collision scene reconstruction from 2001 to 2021 based on the Web of Science database. Knowledge mapping is a cutting-edge research method in scientometric, which has been widely applied in medicine and informatics. Compared with traditional literature review, knowledge mapping with visual techniques identifies hot keywords and key literature in the field more scientifically, and displays them in schematic diagrams intuitively which allows to further predict potential hotspots. A total of 803 original papers are retrieved to analyze and discuss the evolution of the field in the past 20 years, from macro to micro, in term of background information, popular themes, and knowledge structure. Results indicate the number of publications in this field is limited, and collaborations among authors and among institutions are insufficient. In the meantime, mappings imply the top three hot themes being scene reconstruction, computer technology, and injuries. The introduction of AI related technologies, such as neural networks and genetic algorithms, into collision reconstruction would be a potential research direction.
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Affiliation(s)
- Zefang Shen
- China University of Political Science and Law, Beijing 100088, China.
| | - Wei Ji
- Fada Institute of Forensic Medicine & Science, China University of Political Science and Law, Beijing 100088, China.
| | - Shengnan Yu
- Fada Institute of Forensic Medicine & Science, China University of Political Science and Law, Beijing 100088, China.
| | - Gang Cheng
- Fada Institute of Forensic Medicine & Science, China University of Political Science and Law, Beijing 100088, China
| | - Quan Yuan
- State Key Laboratory of Automotive Safety and Energy, School of Vehicle & Mobility, Tsinghua University, Beijing 100084, China.
| | - Zhengqi Han
- China University of Political Science and Law, Beijing 100088, China
| | - Hongxia Liu
- China University of Political Science and Law, Beijing 100088, China
| | - Tiantong Yang
- Fada Institute of Forensic Medicine & Science, China University of Political Science and Law, Beijing 100088, China.
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Guo M, Yuan Z, Janson B, Peng Y, Yue R, Zhang G. Do factors associated with older pedestrian crash severity differ? A causal factor analysis based on exposure level of pedestrians. TRAFFIC INJURY PREVENTION 2023; 24:321-330. [PMID: 36988589 DOI: 10.1080/15389588.2023.2183080] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 02/15/2023] [Accepted: 02/17/2023] [Indexed: 05/23/2023]
Abstract
OBJECTIVE Older pedestrians are more likely to have severe or fatal consequences when involved in traffic crashes. Identifying the factors contributing to the severity and possible interdependencies between factors in specific exposure areas is the first step to improving safety. Therefore, examining the causal factors' impact on pedestrian-vehicle crash severity in a given area is vital for formulating effective measures to reduce the risk of pedestrian fatalities and injuries. METHODS This study implements the Thiessen polygon algorithm deployed to define older pedestrians' exposure influence area. Enabling trip characteristics and built environment information as exposure index settings for the background of the pedestrian severity causal analysis. Then, structural equation modeling (SEM) was applied to conduct a factor analysis of the crash severity in high- and low-exposure areas. The SEM evaluates latent factors such as driver risk attitude, risky driving behavior, lack of risk perception among older pedestrians, natural environment, adverse road conditions for driving or walking, and vehicle conditions. The SEM crash model also establishes the relationship between each latent factor. RESULTS In total, drivers' risky driving behavior (0.270, p < 0.05) in low-exposure areas significantly impacts older pedestrian crash severity more than in high-exposure areas. Lack of risk perception among older pedestrians (0.232, p < 0.05) is the most critical factor promoting crash severity in high-exposure areas. The natural environment (0.634, p < 0.05) in high-exposure areas positively influences older pedestrians' lack of risk perception more than in low-exposure areas. CONCLUSIONS Significant group differences (p-values ∼ 0.001-0.049) existed between the causal factors of the high-exposure risk areas and the low-exposure risk factors. Different exposure intervals require detailed scenarios based on the critical risks identified. The crash severity promotion measures in different exposure areas can be focused on according to the critical causes analyzed. Those clues, in turn, can be used by transportation authorities in prioritizing their plans, policies, and programs toward improving the safety and mobility of older pedestrians.
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Affiliation(s)
- Manze Guo
- Key Laboratory of Transport Industry of Big Data Application Technologies for Comprehensive Transport, Ministry of Transport, School of Traffic and Transportation, Beijing Jiaotong University, Beijing, China
| | - Zhenzhou Yuan
- Key Laboratory of Transport Industry of Big Data Application Technologies for Comprehensive Transport, Ministry of Transport, School of Traffic and Transportation, Beijing Jiaotong University, Beijing, China
| | - Bruce Janson
- Department of Civil Engineering, University of Colorado Denver, Denver, Colorado, USA
| | - Yongxin Peng
- Key Laboratory of Transport Industry of Big Data Application Technologies for Comprehensive Transport, Ministry of Transport, School of Traffic and Transportation, Beijing Jiaotong University, Beijing, China
| | - Rui Yue
- Key Laboratory of Transport Industry of Big Data Application Technologies for Comprehensive Transport, Ministry of Transport, School of Traffic and Transportation, Beijing Jiaotong University, Beijing, China
| | - Guowu Zhang
- Key Laboratory of Transport Industry of Big Data Application Technologies for Comprehensive Transport, Ministry of Transport, School of Traffic and Transportation, Beijing Jiaotong University, Beijing, China
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Mizuno K, Horiki M, Zhao Y, Yoshida A, Wakabayashi A, Hosokawa T, Tanaka Y, Hosokawa N. Analysis of fall kinematics and injury risks in ground impact in car-pedestrian collisions using impulse. ACCIDENT; ANALYSIS AND PREVENTION 2022; 176:106793. [PMID: 35964394 DOI: 10.1016/j.aap.2022.106793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 07/13/2022] [Accepted: 08/02/2022] [Indexed: 06/15/2023]
Abstract
In vehicle-to-pedestrian collisions, pedestrian injuries occur due to contact with the car and the ground. Previous studies investigated pedestrian kinematic behavior using a parameter study or through statistical analysis although the force interaction between the pedestrian and the vehicle has not been considered. In this study, multibody analyses were conducted for vehicle-pedestrian collisions for adult and child pedestrian with various vehicle shapes. The impulse and impulse moment acting on the pedestrian from the vehicle were introduced, and the kinematic behavior, rotation and ground impact of the pedestrian model were examined. It was found that if an impulse moment acts on the pedestrian when the pedestrian re-contacts with the hood of the car, the angular velocity of the pedestrian's torso changes in the opposite direction (away from the car), and the torso angle prior to the ground contact decreases to less than 90°. This re-contact between the pedestrian and the vehicle was more likely to occur for cases where the collision involves an adult pedestrian, lower hood leading edge (HLE), longer hood length, and lower collision velocity. When the pedestrian torso angle in contact with the ground was less than 90°, the head vertical impact velocity with respect to the ground became less than 2.9 m/s which corresponds to the injury threshold of the head. This study demonstrated that pedestrian-vehicle re-contact is crucial for reducing ground injury. The vehicle shape, pedestrian size, and collision velocity can determine whether re-contact of the pedestrian with the vehicle occurs. This can then explain the factors affecting pedestrian ground impact injury (e.g., higher HLE, higher risk of ground head injury for children) that were shown in previous studies. A strategy to mitigate ground injury is to apply enough impulse moment onto the pedestrian's upper body from the hood in order to change the torso angular velocity during re-contact, thus making the torso angle less than 90°prior to the ground contact.
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Affiliation(s)
- Koji Mizuno
- Department of Mechanical Systems Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan.
| | - Masahiro Horiki
- Department of Mechanical Systems Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
| | - Yuqing Zhao
- Department of Mechanical Systems Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
| | - Airi Yoshida
- AD&ADAS Engineering Division 3, DENSO CORPORATION, 1-1, Showa-cho, Kariya, Aichi 448-8661, Japan
| | - Asei Wakabayashi
- AD&ADAS Engineering Division 3, DENSO CORPORATION, 1-1, Showa-cho, Kariya, Aichi 448-8661, Japan
| | - Toshio Hosokawa
- AD&ADAS Engineering Division 3, DENSO CORPORATION, 1-1, Showa-cho, Kariya, Aichi 448-8661, Japan
| | - Yoshinori Tanaka
- Automotive Research Department, National Traffic Safety and Environment Laboratory, 7-42-27 Jindaiji, Higashimachi, Chofu, Tokyo 182-0012 Japan
| | - Naruyuki Hosokawa
- Automotive Research Department, National Traffic Safety and Environment Laboratory, 7-42-27 Jindaiji, Higashimachi, Chofu, Tokyo 182-0012 Japan
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Wang F, Yin J, Hu L, Wang M, Liu X, Miller K, Wittek A. Should anthropometric differences between the commonly used pedestrian computational biomechanics models and Chinese population be taken into account when predicting pedestrian head kinematics and injury in vehicle collisions in China? ACCIDENT; ANALYSIS AND PREVENTION 2022; 173:106718. [PMID: 35640364 DOI: 10.1016/j.aap.2022.106718] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 04/27/2022] [Accepted: 05/17/2022] [Indexed: 06/15/2023]
Abstract
Computational biomechanics models play a key role in predicting/evaluating pedestrian head kinematics and injury risk in car-to-pedestrian collisions. The human multibody models most commonly used in car-to-pedestrian collision reconstruction, such as pedestrian model by The Netherlands Organisation for Applied Scientific Research TNO, are built using the anthropometry of Western European population as defined in TNO (2013) human multibody model database. In this study, we investigate the effects of the anthropometric differences between the Western European and Chinese populations on the pedestrian head kinematics and injury responses predicted using multibody models. The comparison was conducted through car-to-pedestrian collision simulations using pedestrian multibody models representing anthropometric characteristics of Western European and Chinese populations, three typical vehicle shapes (sedan, SUV and minivan), five initial vehicle impact speeds (30, 35, 40, 45, 50 km/h), and six pedestrian walking postures. The results indicate that the change of pedestrian model anthropometry (from Western European to Chinese) exerts appreciable effects on both the predicted initial boundary conditions of the head-to-windscreen impact (in particular the head-to-windscreen impact angle) and the head injury indices in the impact with the road surface (secondary impact).
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Affiliation(s)
- Fang Wang
- School of Automotive and Mechanical Engineering, Changsha University of Science and Technology, Changsha 410114, China
| | - Jiajie Yin
- School of Automotive and Mechanical Engineering, Changsha University of Science and Technology, Changsha 410114, China
| | - Lin Hu
- School of Automotive and Mechanical Engineering, Changsha University of Science and Technology, Changsha 410114, China.
| | - Mingliang Wang
- School of Automotive and Mechanical Engineering, Changsha University of Science and Technology, Changsha 410114, China
| | - Xin Liu
- School of Automotive and Mechanical Engineering, Changsha University of Science and Technology, Changsha 410114, China
| | - Karol Miller
- Intelligent Systems for Medicine Laboratory, Department of Mechanical Engineering, The University of Western Australia, Perth 6009, Western Australia, Australia; Harvard Medical School, Boston, MA, USA
| | - Adam Wittek
- Intelligent Systems for Medicine Laboratory, Department of Mechanical Engineering, The University of Western Australia, Perth 6009, Western Australia, Australia.
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Pan D, Han Y, Wu H, Lin L, Wang B, Huang H. Can emergency avoidance behavior reduce injuries to electric two-wheeler riders in vehicle collisions? TRAFFIC INJURY PREVENTION 2022; 23:422-427. [PMID: 35862929 DOI: 10.1080/15389588.2022.2093352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 06/06/2022] [Accepted: 06/20/2022] [Indexed: 06/15/2023]
Abstract
OBJECTIVES The aim of this study was to examine the effects of emergency avoidance behaviors on the kinematics and injuries of electric two-wheeler (ETW) riders. METHODS Four typical riding postures of ETW riders before collisions, including one normal posture and three avoidance postures, were identified through analysis of 298 videos of vehicle to ETW accidents. Crash simulations were then performed using the Total Human Model of Safety (THUMS) occupant model, ETW and a sedan finite element (FE) model, and the kinematics of ETW riders were compared. The risk of head injury and lower extremity injury was also investigated. RESULTS When the struck foot position of the ETW rider was lower than the ETW pedal, the lower extremity was struck by the sedan bumper and ETW frame from the right and left side respectively, and the upper body of the rider rotated around the hood leading edge. At a car velocity of 40 km/h, the rider was at high risk of head injury and the tibia was fractured. The medial cruciate ligament (MCL) was ruptured in both the 20 km/h and 40 km/h collisions. When the struck foot position of the ETW rider was higher than the pedal, the lower extremity was hit by the bumper and then rebounded. In this situation, the bending moments of the femur and tibia, as well as the bending angle and shear displacement of the knee joint were less than the injury threshold in all crash simulations. Furthermore, when the head was turned toward the colliding car, the risk of head injury varied with the emergency avoidance posture. CONCLUSIONS The height of the struck foot relative to the ETW pedal influenced the rider's global kinematics, and head and lower extremity injuries risk. In the struck side foot landing and both feet landing postures, the lower extremity was restrained and compressed by the ETW frame, resulting in a high risk of tibia fracture and MCL rupture. Reducing the impact velocities could effectively mitigate the injury risk of the ETW riders; however, loading patterns remain an important factor influencing the risk of lower extremity injury.
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Affiliation(s)
- Di Pan
- School of Aerospace Engineering, Xiamen University, Xiamen, China
- School of Mechanical and Automotive Engineering, Xiamen University of Technology, Xiamen, China
| | - Yong Han
- School of Mechanical and Automotive Engineering, Xiamen University of Technology, Xiamen, China
- Fujian Collaborative Innovation Center for R&D of Coach and Special Vehicle, Xiamen, China
| | - He Wu
- School of Aerospace Engineering, Xiamen University, Xiamen, China
- School of Mechanical and Automotive Engineering, Xiamen University of Technology, Xiamen, China
| | - Liya Lin
- School of Mechanical and Automotive Engineering, Xiamen University of Technology, Xiamen, China
- Fujian Collaborative Innovation Center for R&D of Coach and Special Vehicle, Xiamen, China
| | - Bingyu Wang
- School of Mechanical and Automotive Engineering, Xiamen University of Technology, Xiamen, China
- Fujian Collaborative Innovation Center for R&D of Coach and Special Vehicle, Xiamen, China
| | - Hongwu Huang
- School of Aerospace Engineering, Xiamen University, Xiamen, China
- School of Mechanical and Automotive Engineering, Xiamen University of Technology, Xiamen, China
- Fujian Collaborative Innovation Center for R&D of Coach and Special Vehicle, Xiamen, China
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Evaluation of Urban Traffic Accidents Based on Pedestrian Landing Injury Risks. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12126040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In comparison with vehicle-to-pedestrian collision, pedestrian-to-ground contact usually results in more unpredictable injuries (e.g., intracranial, neck, and abdominal injuries). Although there are many studies for different applications of such methods, this paper conducts an in-depth analysis of urban traffic pedestrian accidents. The effects of pedestrian rotation angle (PRA) and pedestrian facing orientation (PFO) on head and neck injury risk in a ground contact are investigated by the finite element numerical models and different probabilistic analyses. It goes without saying that this study provides a theoretical basis for the prediction and protection study of pedestrian ground contact injury risk. In our experiments, 24 pedestrian-to-ground simulations are carried out by the THUMS v4.0.2 model considering eight PRAs (0°, 45°, 90°, 135°, 180°, 225°, 270°, 315°, 360°) and three PFOs (x+, x−, y+). Each test was simulated with loading the average linear and rotational velocities that obtained from real-world pedestrian accidents at the pedestrian’s center of gravity. The results show that both PRAs and PFOs have significant impacts on head and neck injuries. Head HIC value caused by PRA 0–135° is much higher than that caused by PRA 180–315°. Neck injury risk caused by PRA 180° is the greatest one in comparison with other PRAs. The PRAs 90° and 270° usually induce a relatively lower neck injury risk. For PFO, the risk of head and neck injury was lower than PFOy+ and PFOx+ or PFOx−, which means PFOy+ was a safer landing orientation for both head and neck. The potential risk of head and neck injuries caused by the ground contact was strongly associated with the symmetry/asymmetric features of human anatomy.
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Deng G, Wang F, Yu C, Peng Y, Xu H, Li Z, Hou L, Wang Z. Assessment of standing passenger traumatic brain injury caused by ground impact in subway collisions. ACCIDENT; ANALYSIS AND PREVENTION 2022; 166:106547. [PMID: 34954548 DOI: 10.1016/j.aap.2021.106547] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 12/06/2021] [Accepted: 12/17/2021] [Indexed: 06/14/2023]
Abstract
Human head is the most vulnerable region in subway collisions. To design a safer subway, the head impact biomechanical response should be studied first. This paper aims to investigate the standing passenger head-ground impact dynamic response and traumatic brain injury (TBI) in subway collisions. A standing passenger-subway interior dynamic model was numerically developed by using our previous validated finite element (FE)-multibody (MB) coupled human body model, which was integrated by the Total Human Model for Safety (THUMS) head-neck FE model and the extracted remaining body segments pedestrian MB model of TNO. A parametric study considering the handrail type, standing angle, and friction coefficient between the shoes and ground was performed. Results show that the passenger dynamic response could be divided into two categories according to whether the passenger hit handrails. Passenger TBIs severity could be efficiently alleviated by the passenger body (excluding the head) hitting the handrail first before head-ground impact. The probabilities of DAI in the cerebellum and brain stem were low. A statistical analysis of TBIs demonstrated that the risks of TBIs were sensitive to the handrail type in subway collisions, but did not to the standing angle and friction coefficient. This study provides practical help for improving the interior crashworthiness performance of subways.
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Affiliation(s)
- Gongxun Deng
- Key Laboratory of Traffic Safety on Track, Ministry of Education, School of Traffic & Transportation Engineering, Central South University, Changsha 410075, PR China; Joint International Research Laboratory of Key Technology for Rail Traffic Safety, Central South University, Changsha 410075, PR China; Trinity Centre for Bioengineering, Trinity College Dublin, Ireland
| | - Fang Wang
- School of Automotive and Mechanical Engineering, Changsha University of Science & Technology, Changsha 410205, PR China
| | - Chao Yu
- Key Laboratory of Traffic Safety on Track, Ministry of Education, School of Traffic & Transportation Engineering, Central South University, Changsha 410075, PR China; Joint International Research Laboratory of Key Technology for Rail Traffic Safety, Central South University, Changsha 410075, PR China
| | - Yong Peng
- Key Laboratory of Traffic Safety on Track, Ministry of Education, School of Traffic & Transportation Engineering, Central South University, Changsha 410075, PR China; Joint International Research Laboratory of Key Technology for Rail Traffic Safety, Central South University, Changsha 410075, PR China.
| | - Hongzhen Xu
- School of Mechanical and Automotive Engineering, Xiamen University of Technology, Xiamen 361024, PR China
| | - Zhixiang Li
- Key Laboratory of Traffic Safety on Track, Ministry of Education, School of Traffic & Transportation Engineering, Central South University, Changsha 410075, PR China; Joint International Research Laboratory of Key Technology for Rail Traffic Safety, Central South University, Changsha 410075, PR China
| | - Lin Hou
- Key Laboratory of Traffic Safety on Track, Ministry of Education, School of Traffic & Transportation Engineering, Central South University, Changsha 410075, PR China; Joint International Research Laboratory of Key Technology for Rail Traffic Safety, Central South University, Changsha 410075, PR China
| | - Zhen Wang
- School of Mechanical and Automotive Engineering, Xiamen University of Technology, Xiamen 361024, PR China
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12
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Wang F, Wang Z, Hu L, Xu H, Yu C, Li F. Evaluation of Head Injury Criteria for Injury Prediction Effectiveness: Computational Reconstruction of Real-World Vulnerable Road User Impact Accidents. Front Bioeng Biotechnol 2021; 9:677982. [PMID: 34268297 PMCID: PMC8275938 DOI: 10.3389/fbioe.2021.677982] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 05/21/2021] [Indexed: 11/13/2022] Open
Abstract
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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Affiliation(s)
- Fang Wang
- School of Automotive and Mechanical Engineering, Changsha University of Science and Technology, Changsha, China
| | - Zhen Wang
- School of Mechanical and Automotive Engineering, Xiamen University of Technology, Xiamen, China
| | - Lin Hu
- School of Automotive and Mechanical Engineering, Changsha University of Science and Technology, Changsha, China
| | - Hongzhen Xu
- School of Mechanical and Automotive Engineering, Xiamen University of Technology, Xiamen, China
| | - Chao Yu
- School of Mechanical and Automotive Engineering, Xiamen University of Technology, Xiamen, China
| | - Fan Li
- State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha, China
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13
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Wu H, Han Y, Pan D, Wang B, Huang H, Mizuno K, Thomson R. The Head AIS 4+ Injury Thresholds for the Elderly Vulnerable Road User Based on Detailed Accident Reconstructions. Front Bioeng Biotechnol 2021; 9:682015. [PMID: 34249884 PMCID: PMC8261157 DOI: 10.3389/fbioe.2021.682015] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 05/26/2021] [Indexed: 11/14/2022] Open
Abstract
Compared with the young, the elderly (age greater than or equal to 60 years old) vulnerable road users (VRUs) face a greater risk of injury or death in a traffic accident. A contributing vulnerability is the aging processes that affect their brain structure. The purpose of this study was to investigate the injury mechanisms and establish head AIS 4+ injury tolerances for the elderly VRUs based on various head injury criteria. A total of 30 elderly VRUs accidents with detailed injury records and video information were selected and the VRUs’ kinematics and head injuries were reconstructed by combining a multi-body system model (PC-Crash and MADYMO) and the THUMS (Ver. 4.0.2) FE models. Four head kinematic-based injury predictors (linear acceleration, angular velocity, angular acceleration, and head injury criteria) and three brain tissue injury criteria (coup pressure, maximum principal strain, and cumulative strain damage measure) were studied. The correlation between injury predictors and injury risk was developed using logistical regression models for each criterion. The results show that the calculated thresholds for head injury for the kinematic criteria were lower than those reported in previous literature studies. For the brain tissue level criteria, the thresholds calculated in this study were generally similar to those of previous studies except for the coup pressure. The models had higher (>0.8) area under curve values for receiver operator characteristics, indicating good predictive power. This study could provide additional support for understanding brain injury thresholds in elderly people.
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Affiliation(s)
- He Wu
- School of Aeronautics and Astronautics, Xiamen University, Xiamen, China.,School of Mechanical and Automotive Engineering, Xiamen University of Technology, Xiamen, China
| | - Yong Han
- School of Mechanical and Automotive Engineering, Xiamen University of Technology, Xiamen, China
| | - Di Pan
- School of Aeronautics and Astronautics, Xiamen University, Xiamen, China.,School of Mechanical and Automotive Engineering, Xiamen University of Technology, Xiamen, China
| | - Bingyu Wang
- School of Mechanical and Automotive Engineering, Xiamen University of Technology, Xiamen, China
| | - Hongwu Huang
- School of Aeronautics and Astronautics, Xiamen University, Xiamen, China.,School of Mechanical and Automotive Engineering, Xiamen University of Technology, Xiamen, China
| | - Koji Mizuno
- Department of Mechanical Science and Engineering, Graduate School of Engineering, Nagoya University, Nagoya, Japan
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14
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Pak W, Grindle D, Untaroiu C. The Influence of Gait Stance and Vehicle Type on Pedestrian Kinematics and Injury Risk. J Biomech Eng 2021; 143:1109472. [PMID: 34008836 DOI: 10.1115/1.4051224] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Indexed: 11/08/2022]
Abstract
Pedestrians are one of the most vulnerable road users. In 2019, the USA reported the highest number of pedestrian fatalities number in nearly three decades. To better protect pedestrians in car-to-pedestrian collisions (CPC), pedestrian biomechanics must be better investigated. The pre-impact conditions of CPCs vary significantly in terms of the characteristics of vehicles (e.g., front-end geometry, stiffness, etc.) and pedestrians (e.g., anthropometry, posture, etc.). The influence of pedestrian gait posture has not been well analyzed. The purpose of this study was to numerically investigate the changes in pedestrian kinematics and injuries across various gait postures in two different vehicle impacts. Five finite element (FE) human body models, that represent the 50th percentile male in gait cycle, were developed and used to perform CPC simulations with two generic vehicle FE models representing a low-profile vehicle and a high-profile vehicle. In the impacts with the high-profile vehicle, a sport utility vehicle, the pedestrian models usually slide above the bonnet leading edge and report shorter wrap around distances than in the impacts with a low-profile vehicle, a family car/sedan (FCR). The pedestrian postures influenced the postimpact rotation of the pedestrian and consequently, the impacted head region. Pedestrian posture also influenced the risk of injuries in the lower and upper extremities. Higher bone bending moments were observed in the stance phase posture compared to the swing phase. The findings of this study should be taken into consideration when examining pedestrian protection protocols. In addition, the results of this study can be used to improve the design of active safety systems used to protect pedestrians in collisions.
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Affiliation(s)
- Wansoo Pak
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061
| | - Daniel Grindle
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061
| | - Costin Untaroiu
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061
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15
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Evaluation of injury thresholds for predicting severe head injuries in vulnerable road users resulting from ground impact via detailed accident reconstructions. Biomech Model Mechanobiol 2020; 19:1845-1863. [PMID: 32133546 DOI: 10.1007/s10237-020-01312-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 02/17/2020] [Indexed: 10/24/2022]
Abstract
The aim of this study was to evaluate the effectiveness of various head injury criteria and associated risk functions in prediction of vulnerable road users (VRUs) severe head injuries caused by ground impact during vehicle collisions. Ten VRU accidents with video information were reconstructed by using Chalmers Pedestrian Model, vehicle multi-body system models and the THUMS (Ver. 4.0.2) finite element model. The head kinematics were used to calculate injury risks for seven head kinematics-based criteria: head angular velocity and acceleration, linear acceleration, head injury criterion (HIC), head impact power (HIP) and two versions of brain injury criterion (i.e., BRIC and BrIC). In addition, the intracranial responses were used to estimate seven tissue injury criteria, Von Mises stress, shear stress, coup pressure (C.P.) and countercoup pressure (CC.P.), maximum principal strain (MPS), cumulative strain damage measure (CSDM), and dilatation damage measure (DDM). A review of the medical reports for all cases indicated that each individual suffered severe head injuries and died. The injury risks predicted through simulations were compared to the head injuries recorded in the medical or forensic reports. The results indicated that 75-100% of the reconstructed ground impact accidents injuries were correctly predicted by angular acceleration, linear acceleration, HIC, C.P., MPS and CSDM0.15. Shear stress, CC.P. and CSDM0.25 correctly predicted 50-75% of the reconstructed accidents injuries. For angular velocity, HIP, BRIC and BrIC, the injuries were correctly predicted for less than 50% of the reconstructed accidents. The Von Mises stress and DDM did not correctly predict any reconstructed accidents injuries. The results could help to understand the effectiveness of the brain injury criteria for future head injury evaluation.
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16
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A Computational Biomechanics Human Body Model Coupling Finite Element and Multibody Segments for Assessment of Head/Brain Injuries in Car-To-Pedestrian Collisions. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17020492. [PMID: 31941003 PMCID: PMC7014246 DOI: 10.3390/ijerph17020492] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 12/22/2019] [Accepted: 01/08/2020] [Indexed: 11/23/2022]
Abstract
It has been challenging to efficiently and accurately reproduce pedestrian head/brain injury, which is one of the most important causes of pedestrian deaths in road traffic accidents, due to the limitations of existing pedestrian computational models, and the complexity of accidents. In this paper, a new coupled pedestrian computational biomechanics model (CPCBM) for head safety study is established via coupling two existing commercial pedestrian models. The head–neck complex of the CPCBM is from the Total Human Model for Safety (THUMS, Toyota Central R&D Laboratories, Nagakute, Japan) (Version 4.01) finite element model and the rest of the parts of the body are from the Netherlands Organisation for Applied Scientific Research (TNO, The Hague, The Netherlands) (Version 7.5) multibody model. The CPCBM was validated in terms of head kinematics and injury by reproducing three cadaveric tests published in the literature, and a correlation and analysis (CORA) objective rating tool was applied to evaluate the correlation of the related signals between the predictions using the CPCBM and the test results. The results show that the CPCBM head center of gravity (COG) trajectories in the impact direction (YOZ plane) strongly agree with the experimental results (CORA ratings: Y = 0.99 ± 0.01; Z = 0.98 ± 0.01); the head COG velocity with respect to the test vehicle correlates well with the test data (CORA ratings: 0.85 ± 0.05); however, the correlation of the acceleration is less strong (CORA ratings: 0.77 ± 0.06). No significant differences in the behavior in predicting the head kinematics and injuries of the tested subjects were observed between the TNO model and CPCBM. Furthermore, the application of the CPCBM leads to substantial reduction of the computation time cost in reproducing the pedestrian head tissue level injuries, compared to the full-scale finite element model, which suggests that the CPCBM could present an efficient tool for pedestrian brain-injury research.
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17
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Huang Y, Zhou Q, Koelper C, Li Q, Nie B. Are riders of electric two-wheelers safer than bicyclists in collisions with motor vehicles? ACCIDENT; ANALYSIS AND PREVENTION 2020; 134:105336. [PMID: 31704640 DOI: 10.1016/j.aap.2019.105336] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 09/23/2019] [Accepted: 10/16/2019] [Indexed: 06/10/2023]
Abstract
Electric two-wheelers (E2Ws) have become newly popular transportation tools with the associated growing traffic safety concerns. E2W riders and bicyclists behave similarly as vulnerable road users (VRUs), while exhibited dissimilarities in riding postures and interactions with the two-wheelers. Existing epidemiology reveals prominent differences in injury risks between E2W riders and other vulnerable road users in collisions with motor vehicles. The objective of this study is to investigate the factors influencing kinematics and head injury risks of two-wheeler rides in two-wheeler-vehicle collisions and compare between E2W-vehicle and bicycle-vehicle collisions. Via multi-body modeling of two two-wheeler types, two vehicle types, and three rider statures in MADYMO, twelve collision scenarios were developed. A simulation matrix considering a range of impact velocities and relative positions was performed for each scenario. A subsequent parametric analysis was conducted with focus on the kinematics and head injury risks of two-wheeler riders. Results show that the head injury risk increased with vehicle moving velocity, while the two-wheeler velocity and relative location between rider and vehicle prior to the collision exhibited highly non-linear influence on the kinematical response. The rider with larger stature had higher possibilities to miss head impact on the vehicle. In collisions with the sedan, E2W riders would sustain lower head injury risks with lower contacting velocity on the windshield than bicyclists. While in collisions with the SUV, E2W riders would sustain increasing head injury risks due to the higher structural stiffness at contact, and the risk level was about the same as bicyclists. The findings revealed the loading mechanisms behind the different head injury risks between E2W riders and bicyclists.
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Affiliation(s)
- Yuan Huang
- State Key Laboratory of Automotive Safety and Energy, School of Vehicle and Mobility, Tsinghua University, Beijing 100084, China
| | - Qing Zhou
- State Key Laboratory of Automotive Safety and Energy, School of Vehicle and Mobility, Tsinghua University, Beijing 100084, China
| | - Caroline Koelper
- State Key Laboratory of Automotive Safety and Energy, School of Vehicle and Mobility, Tsinghua University, Beijing 100084, China
| | - Quan Li
- State Key Laboratory of Automotive Safety and Energy, School of Vehicle and Mobility, Tsinghua University, Beijing 100084, China
| | - Bingbing Nie
- State Key Laboratory of Automotive Safety and Energy, School of Vehicle and Mobility, Tsinghua University, Beijing 100084, China.
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18
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Zou T, Shang S, Simms C. Potential benefits of controlled vehicle braking to reduce pedestrian ground contact injuries. ACCIDENT; ANALYSIS AND PREVENTION 2019; 129:94-107. [PMID: 31132748 DOI: 10.1016/j.aap.2019.05.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 04/11/2019] [Accepted: 05/07/2019] [Indexed: 06/09/2023]
Abstract
Protecting struck pedestrians during the ground contact phase has been a challenge for decades. Recent studies have shown how ground related injury is influenced by pedestrian kinematics. In this paper we further developed this approach by assessing the potential of controlling vehicle braking to reduce pedestrian ground contact injuries. Applying a recently proposed Simulation Test Sample, a series of simulations were run using the MADYMO software environment. The approach considered 6 vehicle shapes, 4 pedestrian models, 3 impact velocities and 2 pedestrian gaits and each case was considered with two different vehicle braking approaches. The first was full braking, while the second applied controlled braking, for which a strategy based on pedestrian kinematics was applied. The effect of vehicle braking was evaluated using the Weighted Injury Cost (WIC) of overall pedestrian injuries and the pedestrian-ground impact velocity change. The proximity of the vehicle and pedestrian at the instant of ground contact was also evaluated to assess the potential of future vehicle based intervention methods to cushion the ground contact. Finally real-world videos of pedestrian collisions were analyzed to estimate the available free vehicle stopping distances. Results showed substantial median reductions in WIC and head impact velocity for all vehicle shapes except the Van. The proximity of the pedestrian to the vehicle front at the instant of ground contact under controlled braking is less than 1.5 m in most cases, and the required stopping distance for the vehicle under controlled braking was within the available stopping distance estimated from the video footage in about 74% of cases. It is concluded that controlled braking has significant potential to reduce the overall burden of pedestrian ground contact injuries, but future efforts are required to establish an optimized braking strategy as well as a means to handle those cases where controlled braking is not beneficial or even harmful.
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Affiliation(s)
- Tiefang Zou
- School of Automobile and Mechanical Engineering, Changsha University of Science and Technology, Changsha, 410114, China; Centre for Bioengineering, School of Engineering, Trinity College Dublin, Dublin, 2, Ireland; Key Laboratory of Safety Design and Reliability Technology for Engineering Vehicle, Hunan Province, 410114, China
| | - Shi Shang
- Centre for Bioengineering, School of Engineering, Trinity College Dublin, Dublin, 2, Ireland
| | - Ciaran Simms
- Centre for Bioengineering, School of Engineering, Trinity College Dublin, Dublin, 2, Ireland.
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