scholarly journals THE DEVELOPMENT OF A CONFLICT HAZARDOUS ASSESSMENT MODEL FOR EVALUATING URBAN INTERSECTION SAFETY / TRANSPORTO PRIEMONIŲ SUSIDŪRIMO PAVOJAUS VERTINIMO MODELIO RAIDA, ANALIZUOJANT SUSIKIRTIMO TAŠKŲ SAUGĄ MIESTO SANKRYŽOSE / МОДЕЛЬ ОЦЕНКИ УГРОЗЫ СТОЛКНОВЕНИЯ ТРАНСПОРТНЫХ СРЕДСТВ ДЛЯ АНАЛИЗА БЕЗОПАСНОСТИ ГОРОДСКИХ ПЕРЕКРЕСТКОВ

Transport ◽  
2011 ◽  
Vol 26 (2) ◽  
pp. 216-223 ◽  
Author(s):  
Sien Zhou ◽  
Jian Sun ◽  
Xiao An ◽  
Keping Li
Keyword(s):  
Head Injury ◽  
Traffic Safety ◽  
Assessment Model ◽  
Evaluation Procedure ◽  
Mechanism Analysis ◽  
Mixed Traffic ◽  
Rapid Urbanization ◽  
Crash Data ◽  
Injury Criteria ◽  
Head Injury Criteria

Road safety conditions in China have worsened following rapid urbanization and motorization. For a long time now, China has ranked first in the world in the number of road accidents and fatalities. Therefore, evaluating safety levels is essential to implementing effective countermeasures. For developing countries like China, however, assessing safety levels via crash data statistical analysis is difficult because of limitations on a short history of collecting crash data, small samples and an incomplete collection of information. To address these limitations, the method of surrogate safety analysis using the traffic conflict technique (TCT) has become a widely used evaluation procedure. On the basis of the mechanism analysis of TCT, the paper presents a conflict hazardous assessment model (CHAM) for the mixed traffic safety evaluation of urban intersections. In the proposed model, the principle of the conservation of momentum is used. CHAM is a model used for assessing safety levels from the aspects of severe conflict numbers and conflict hazardous levels (CHLs) when traffic conflicts among mixed-traffic modes occur. Factors such as the conflict type and conflict angle of different traffic modes, weight and velocity are considered and incorporated into the model through the integration of the accident collision theory and the head injury criterion (HIC) index for head hazard assessments. The calibration and validation of CHL models are also carried out using 341 intersection crash reports in Beijing from 2006 to 2008. The results show that the established CHL models have good validity. Santrauka Greita urbanizacija ir transporto priemonių skaičiaus didėjimas pablogino kelių saugos sąlygas Kinijoje, kuri jau ilgą laiką pirmauja pasaulyje pagal keliuose įvykstančių nelaimingų atsitikimų ir mirčių skaičių. Todėl saugaus eismo lygio vertinimas ypač svarbus diegiant veiksmingas atsakomąsias priemones. Tokiose besivystančiose šalyse kaip Kinija saugaus eismo lygio vertinimas, pasitelkiant statistinius duomenis apie įvykusius nelaimingus atsitikimus, yra sudėtingas dėl nepakankamai ar netiksliai surinktų duomenų. Remiantis eismo įvykio mechanizmo analize, straipsnyje pristatomas transporto priemonių susidūrimo pavojaus vertinimo modelis, analizuojant įvairių transporto priemonių saugą miesto sankryžose. Pateiktame modelyje naudojamas judesio kiekio tvermės dėsnis. Modelis naudojamas įvertinant saugaus eismo lygius, atsižvelgiant į ypatingus atvejus ir susidūrimo pavojaus lygį, kai eismo įvykiai nutinka tarp skirtingų kategorijų transporto priemonių. Susidūrimo tipas, skirtingų transporto priemonių susidūrimo kampas, svoris ir greitis yra veiksniai, į kuriuos turi būti atsižvelgiama ir kurie yra modelio sudėtinės dalys, sujungiant į visumą transporto priemonių susidūrimo teoriją bei galvos traumų kriterijaus (HIC – head injury criteria) rodiklį. Modelis tikrinamas remiantis informacija apie transporto priemonių susidūrimus Pekine (Kinija) 2006–2008 m. Gauti rezultatai parodė, kad sukurtas modelis yra veiksminga priemonė. Резюме Быстрая урбанизация и темп увеличения количества транспортных средств на дорогах Китая резко ухудшили безопасность дорожного движения. Китай на протяжении многих лет лидирует по числу несчастных случаев (в том числе и со смертельным исходом), происходящих на дорогах. Поэтому оценка уровня безопасности дорожного движения имеет огромное значение при внедрении соответствующих мер. В таких развивающихся странах, как Китай, оценка уровня безопасности дорожного движения с использованием статистических данных осложняется и неэффективна из-за нехватки собранных данных, а зачастую и их неточности. В статье представлена модель оценки угрозы столкновения транспортных средств на городских перекрестках, которая основана на анализе механизма дорожно-транспортного происшествия. В представленной модели используется закон сохранения количества движения. Модель применяется для оценки уровня безопасности дорожного движения с учетом особых случаев, уровня угрозы столкновения и разных категорий транспортных средств. Составными частями модели являют ся тип столкновения, угол столкновения, масса и скорость движения транспортных средств. В модель также включена теория столкновения транспортных средств и критерий тяжести повреждений головы (HIC – head injury criteria). Модель проверена на основе информации о столкновениях транспортных средств в г. Пекине (Китай) в 2006–2008 гг. Полученные результаты свидетельствовали о достоверности представленной модели.

scholarly journals Numerical Simulation of Airbag and Study on the Effect of Airbag Parameters on Head Injury Criteria

2021 ◽  
Vol 9 (9) ◽  
pp. 1654-1666
Author(s):  
Aakash R
Keyword(s):  
Finite Element ◽  
Head Injury ◽  
Traffic Safety ◽  
Critical Role ◽  
Highway Traffic ◽  
Element Analysis ◽  
National Highway Traffic Safety ◽  
Occupant Safety ◽  
Injury Criteria ◽  
Head Injury Criteria

Abstract: In the case of an accident, inflatable restraints system plays a critical role in ensuring the safety of vehicle occupants. Frontal airbags have saved 44,869 lives, according to research conducted by the National Highway Traffic Safety Administration (NHTSA).Finite element analysis is extremely important in the research and development of airbags in order to ensure optimum protection for occupant. In this work, we simulate a head impact test with a deploying airbag and investigate the airbag's parameters. The airbag's performance is directly influenced by the parameters of the cushion such as vent area and fabric elasticity. The FEM model is analysed to investigate the influence of airbag parameter, and the findings are utilised to determine an optimal value that may be employed in the construction of better occupant safety systems. Keywords: airbag, finite element method, occupant safety, frontal airbag, vent size, fabric elasticity, head injury criteria

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.

Performance of Hood System and Head Injury Criteria Subjected to Frontal Impacts

2012 ◽  
Vol 165 ◽  
pp. 270-274 ◽  
Author(s):  
J. Mai Nursherida ◽  
Sahari B. Barkawi ◽  
A.A. Nuraini ◽  
Aidy Ali ◽  
A.A. Faieza ◽  
...  
Keyword(s):  
Head Injury ◽  
Mild Steel ◽  
Epoxy Composite ◽  
Important Variable ◽  
Plane Failure ◽  
Head Injury Criterion ◽  
Frontal Impacts ◽  
Injury Criteria ◽  
Head Injury Criteria ◽  
Protective Performance

The aim of this study is to analyze the effect of steel and composite material on pedestrian head injury criteria of hood system. The hood is made of mild steel and aluminum, e-glass/epoxy composite and carbon epoxy composite are studied and characterized by impact modeling using LS-DYNA V971 in accordance with United States New Car Assessment Program (US-NCAP) frontal impact velocity and based on European Enhanced Vehicle-safety Committee. The most important variable of this structure are mass, material, internal energy, and Head Injury Criterion (HIC). The results are compared with hood made of mild steel. Three types of materials are used which consists of mild steel as reference materials, Aluminum AA5182, E-glass/epoxy composite and carbon fiber/epoxy composite with four different fiber configurations. The in-plane failure behaviors of the composites were evaluated by using Tsai Wu failure criterion. The results for the composite materials are compared to that of steel to find the best material with lowest HIC values. In order to evaluate the protective performance of the baseline hood, the Finite Element models of 50th percentile an adult pedestrian dummy is used in parallel to impact the hood. It was found that aluminum AA5182 hood can reduce the Head Injury Criterion (HIC) by comparing with the baseline hood. For pedestrian crash, it is observed that Aluminum AA5182 hood gave the lowest HIC value with 549.70 for HIC15 and 883.00 for HIC36 followed by steel hood with 657.40 for HIC15 and 980.90 for HIC36, e-glass/epoxy composite hood with 639.60 for HIC15 and 921.70 for HIC36 and carbon/epoxy composite hood with 1197.00 for HIC15 and 1424.00 for HIC36.

FOCUS Headform Testing Used to Evaluate Head Injury Risk for Ejected Riders of Personal Watercraft

2017 ◽  
Author(s):  
Chimba Mkandawire ◽  
Eric S. Winkel ◽  
Nicholas A. White ◽  
Edward Schatz
Keyword(s):  
Brain Injury ◽  
Head Injury ◽  
Injury Risk ◽  
Skull Fractures ◽  
Facial Fractures ◽  
Injury Criteria ◽  
Facial Skull ◽  
Personal Watercraft ◽  
Wide Variability ◽  
Head Injury Criteria

Operators of personal watercraft (PWC) can perform maneuvers that may result in riders separating from the moving watercraft; the tested hypothesis was whether substantial brain injury concurrent with substantial facial and skull fractures can occur from contact with the PWC during a fall. The present study reports the potential for AIS2+ facial/skull fractures and AIS2+ traumatic brain injury (TBI) during a generic fall from the PWC in the absence of wave-jumping or other aggressive maneuvers. While it is well known that PWC can be used for wave-jumping which can result in more severe impacts, such impacts are beyond the scope of the present study because of the wide variability in occupant and PWC kinematics and possible impact velocities and orientations. Passenger separation and fall kinematics from both seated and standing positions were analyzed to estimate head impact velocities and possible impact locations on the PWC. A special purpose headform, known as the Facial and Ocular CountermeasUre Safety (FOCUS) device was used to evaluate the potential for facial fractures, skull fractures and TBI. Impacts between the FOCUS headform and the PWC were performed at velocities of 8, 10, and 12 miles per hour at 5 locations near the stern of a PWC. This study reports impact forces for various facial areas, linear and angular head accelerations, and Head Injury Criteria (HIC). The risk for facial fracture and TBI are reported herein. The results of this study indicate that concurrent AIS2 facial fractures, AIS2+ skull fractures, and AIS2+ TBI do not occur during a simple fall from a PWC.

Design and Validation of a Component Head Injury Criteria Tester for Aerospace Applications

2005 ◽  
Author(s):  
Hamid M. Lankarani ◽  
C. S. Koshy ◽  
C. K. Thorbole
Keyword(s):  
Head Injury ◽  
Seat Belt ◽  
Impact Angle ◽  
Head Impact ◽  
Aircraft Cabins ◽  
Aerospace Applications ◽  
Injury Criteria ◽  
Test Conditions ◽  
Head Injury Criteria ◽  
Impact Events

The compliance with Head Injury Criteria (HIC) specified in 14 CFR 23.562 [1] and CFR 25.562 [2] poses a significant problem for many segments of the aerospace industry. The airlines and the manufacturers of jet transports have made claims of high costs and significant schedule overruns during the development and certification of 16G seats because of the difficulties encountered in meeting this requirement. The current practice is to conduct Full Scale Sled Tests (FSST) on impact sleds. This approach can be expensive, since a new seat may be needed for each test. Moreover, some consider the HIC sensitive to changes in the test conditions, such as sled pulse, seat belt elongation, etc., resulting in HIC results from FSSTs showing poor repeatability. These difficulties make it desirable to devise a cheaper, faster, and more repeatable alternative to FSSTs. This paper describes an attempt to address these issues by designing a device, the National Institute for Aviation Research (NIAR) HIC Component Tester (NHCT) using various multibody tools. This device was then fabricated and its performance evaluated against FSSTs conducted under similar test conditions for some typical impact events that occur in an aircraft cabins e.g. impact with bulkheads. The factors compared for this evaluation are the head impact angle, head impact velocity, HIC, HIC window, peak head C.G. resultant acceleration, average head C.G. resultant acceleration, and head C.G. resultant acceleration profiles. The results of these evaluations show that the NHCT already produces test results that correlate significantly with FSST results for impact targets such as bulkheads and its target envelope is expected eventually to include objects such as seat backs.

Responses of Hybrid-III 50th and Thor-NT 50th in Sled Tests With Different Seat Belt Pretensioner Configurations

2006 ◽  
Author(s):  
Chang In Paek ◽  
Greg Shaw ◽  
Jeff Crandall ◽  
Yoon Ho Baek ◽  
Ol Suk Ko
Keyword(s):  
Head Injury ◽  
Seat Belt ◽  
Relative Sensitivity ◽  
Forward Movement ◽  
Similar Test ◽  
Injury Criteria ◽  
Hybrid Iii ◽  
Head Injury Criteria ◽  
Test Repeatability

This study quantifies the effectiveness of the various seat belt pretensioner configurations relative to the no pretensioner condition and defines the relative sensitivity of the Hybrid-III 50th and THOR-NT 50th percentile male anthropomorphic test devices to pretensioner effects. The results of this study indicate that pretensioners reduced the chest accelerations and Head Injury Criteria (HIC) of both Hybrid-III and THOR-NT dummies. In addition, the pretensioners reduced the chest forward movement by providing restraint earlier in the event. The dual pretensioners and the retractor pretensioners were more effective than the buckle pretensioner and the no pretensioner conditions. Although the Hybrid-III and THOR-NT were different in construction and sitting depth, the Hybrid-III and THOR-NT's responses to the pretensioner conditions were similar. Test-to-test repeatability was acceptable for both dummies.

scholarly journals ASSESSMENT OF HEAD INJURY CRITERIA AND CHEST SEVERITY INDEX FOR FRONTAL IMPACT

2015 ◽  
Vol 8 ◽  
pp. 1376-1382 ◽  
Author(s):  
M.S. Salwani ◽  
◽  
B.B. Sahari ◽  
Aidy Ali ◽  
A.A. Nuraini ◽  
...  
Keyword(s):  
Head Injury ◽  
Severity Index ◽  
Frontal Impact ◽  
Injury Criteria ◽  
Head Injury Criteria

Performance Evaluation of HIC Component Testing Device With a Flexible Neck Using Computational Model

2008 ◽  
Author(s):  
Chandrashekhar K. Thorbole ◽  
Hamid M. Lankarani
Keyword(s):  
Head Injury ◽  
Computational Model ◽  
Full Scale ◽  
Test Method ◽  
Crash Test ◽  
Testing Device ◽  
Dynamic Conditions ◽  
Component Testing ◽  
Injury Criteria ◽  
Head Injury Criteria

The Head Injury Criteria (HIC) compliance is an important aircraft interior furnishing certification. This certification confirms the compliance of the HIC requirement as per 14CFR 23.562 [1] and 14 CFR 25.562 [2]. Full scale crash sled tests are widely used destructive test method to show the required compliance of head injury criteria. This method is costly, time consuming and non repeatable. Factors such as sled pulse shape, belt slack, seating posture of the dummy results change in the dynamic conditions which ultimately affect the HIC value. This poses a significant challenge and high costs to the manufactures to show the compliance of aircraft interior furnishings for the certification process. These factors compel the development of alternative method to certify the cabin furnishings for HIC compliance without consuming aircraft seats, which is more repeatable and non time consuming. The laboratory HIC component tester is the device developed to duplicate the full scale crash HIC result. This device is capable to produce similar dynamic conditions upon impact with the test article resulting duplication of the full scale crash test result. The current model is developed with the rigid neck of polycarbonate unlike the flexible neck of Hybrid II part 572 ATD (Anthropomorphic Test Dummy). This study investigates the scope of improvement in dynamic characteristic of the HCTD (HIC Component Testing Device) with flexible neck. Flexible neck performance is evaluated using validated computational model of the HCTD. The computational model is used to simulate the correlation between the HCTD with rigid neck and HCTD with flexible neck with FSST (Full Scale Sled Test). The result demonstrates that HTCD correlates well with the FSST when flexible neck is used and provides conservative results with rigid neck.

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