An Improved Dummy Neck Assembly for Dynamic Rollover Testing

2010 ◽  
Author(s):  
Jacqueline G. Paver ◽  
Justin Caplinger ◽  
Garrett Mattos ◽  
Donald Friedman
Keyword(s):  
Real World ◽  
Muscle Tension ◽  
Human Head ◽  
Matched Pair ◽  
Neck Injuries ◽  
Stiff Neck ◽  
Ongoing Research ◽  
Compliance Testing ◽  
Hybrid Iii ◽  
Rollover Crash

In the U.S., more than 27,000 catastrophic and fatal injuries occur annually in rollover crashes. Due to the incidence and severity of injuries in rollover crashes, a strategy for injury mitigation is dynamic compliance testing with dummy-occupied vehicles and occupant protection requirements, similar to that required for frontal and side impacts. Presently, there are dynamic vehicle rollover test devices like the Controlled Rollover Impact System and the Jordan Rollover System that realistically recreate real-world rollover crash scenarios. However, the Hybrid III dummy, which is considered to be the best available human surrogate for dynamic rollover tests, has a very stiff neck with limited biofidelity in rollover crashes; the Hybrid III neck is much stiffer than the human neck. Catastrophic human head or neck injuries resulting from roof interaction and partial ejection in real-world rollover crashes are poorly replicated by dynamic rollover tests with the non-biofidelic Hybrid III dummy neck. Only with a more biofidelic dummy can effective testing result in injury mitigation in rollover crashes. This study is part of an ongoing research project aimed at mitigating catastrophic human neck injuries in real-world rollover crashes. The goal was to develop a biofidelic neck assembly for the Hybrid III dummy in rollover crash environments. The design goals of this prototype neck included decreased stiffness and a mechanism that represents the unknowable human muscle tension in rollover crash environments. This paper and its companion paper in this conference introduce the new neck design, present results of matched-pair tests that compare the responses of the new neck with the production Hybrid III neck, and propose preliminary rollover injury criteria for this neck. The neck demonstrates repeatability, improved biofidelity, which results in more realistic occupant kinematics, dynamics, injury prediction, and evaluation of various countermeasures.

Testing of the Prototype Low-Durometer Hybrid III Neck for Improved Biofidelity

2010 ◽  
Author(s):  
Jacqueline G. Paver ◽  
Justin Caplinger ◽  
Garrett Mattos ◽  
Donald Friedman
Keyword(s):  
Real World ◽  
Empirical Relationship ◽  
Lower Hybrid ◽  
Neck Injuries ◽  
Ongoing Research ◽  
Impact Speed ◽  
Axial Forces ◽  
Hybrid Iii ◽  
Parametric Studies ◽  
Impact Duration

This study is part of an ongoing research project aimed at mitigating catastrophic human neck injuries, predominantly due to neck bending, in rollover crashes. Presently, the Hybrid III dummy is considered to be the best available human surrogate for dynamic rollover tests. However, there are known biofidelity and instrumentation limitations associated with its use to predict catastrophic neck injuries in real-world rollover crashes. A previous study investigated the use of the non-biofidelic Hybrid III dummy in a dynamic rollover test to accurately predict the predominant human neck bending injury sustained in real-world rollover crashes. An empirical relationship between upper and lower Hybrid III neck loading was derived. The effects of neck preflexion angle, roof impact speed, roof crush, onset-to-peak neck axial forces and moments, and impact duration on neck bending injury were identified. Peak neck injury measures were rejected. For this study, the 67-durometer Hybrid III production neck was fabricated with more compliant 35-durometer butyl rubber in order improve the dummy biofidelity in rollover tests. The tests in the previous study were repeated. Correlations were established between the prototype and production necks. Parametric studies of the prototype neck revealed similar trends as observed with the Hybrid III production neck.

Prediction of Human Neck Injury in Rollovers From Dynamic Tests Using the Hybrid III Dummy

2008 ◽  
Author(s):  
Donald Friedman ◽  
Jacqueline G. Paver ◽  
Justin Caplinger ◽  
Fred Carlin ◽  
David Rohde
Keyword(s):  
Logistic Regression ◽  
Neck Injury ◽  
Neck Flexion ◽  
Neck Injuries ◽  
Dynamic Tests ◽  
Ongoing Research ◽  
Regression Curves ◽  
Hybrid Iii ◽  
The U.S ◽  
Injury Potential

In the U.S, there are approximately 27,000 occupants seriously injured or killed annually in rollover crashes. This study is part of an ongoing research project aimed at mitigating catastrophic human neck injuries in rollovers using results of dynamic tests, which utilize Hybrid III dummies as human surrogates. A methodology is being developed for replicating, predicting, and differentiating between axial compression and the more predominant neck flexion injuries. This paper presents platen tests, which were performed to determine Hybrid III dummy positioning and instrumentation for use in dynamic rollover tests. In addition, this paper demonstrates the use of the Pintar, et al. logistic regression curves to predict the probability of major flexion neck injury in the human from measured and adjusted Hybrid III dummy neck data. The capability of the Hybrid III dummy neck to realistically evaluate human neck injury potential is discussed.

A destructible headform for the assessment of sports impacts

2021 ◽  
pp. 175433712110559
Author(s):  
Ben Stone ◽  
Sean Mitchell ◽  
Yusuke Miyazaki ◽  
Nicholas Peirce ◽  
Andy Harland
Keyword(s):  
Human Subjects ◽  
Permanent Deformation ◽  
Human Head ◽  
Local Deformation ◽  
Resonance Excitation ◽  
Destructive Testing ◽  
Head Impacts ◽  
Resonance Frequencies ◽  
Hybrid Iii ◽  
Athletic Equipment

Commercially available headforms, such as the Hybrid-III and EN 960 headforms, have been used effectively to investigate the mechanics of head impacts. These headforms may result in accelerations that are unrepresentative of a human head in some impact scenarios. This may be important when considering impacts that produce areas of high pressure, since skull deformation and resonance excitation may influence the dynamic response. The National Operating Committee on Standards for Athletic Equipment (NOCSAE) headform may produce a more suitable response during these types of impacts due to the more representative skull component. However, permanent deformation may occur in some unprotected impact scenarios, resulting in the entire headform needing to be replaced. This paper outlines the development of a novel, modular and destructible headform (LU headform) that can be used in potentially destructive testing, where individual components can be replaced. The LU headform was modelled after a UK 50th percentile male. The inertial properties of the LU headform were within 6% of those observed in humans. The skull simulant properties were within the range of values reported for human tissue in two build orientations, but lower in one build orientation. The lowest and highest resonance frequencies observed in the headform model were within 5% of those observed in humans. Drop and projectile tests were conducted in line with previous cadaver tests with the observed accelerations within the range reported for post-mortem human subjects. The LU headform offers a practical means of simulating head dynamics during localised unprotected impacts or in protected impacts where local deformation and/or resonance frequency excitation remains possible.

scholarly journals Developing Brain-Strain-Based Scaling to Inform the Clinical Relevance of Mouse Models of Concussion Induced by Rotation

2021 ◽  
Author(s):  
Xingyu Liu ◽  
Lihong Lu ◽  
Kewei Bian ◽  
Arthur Brown ◽  
Haojie Mao
Keyword(s):  
Brain Injury ◽  
Real World ◽  
Clinical Relevance ◽  
Neuronal Damage ◽  
Animal Experiments ◽  
Human Head ◽  
Axial Rotation ◽  
Head Impacts ◽  
Flexion Extension ◽  
Human And Mouse

Abstract Background Laboratory animal experiments are an invaluable tool for studying mild traumatic brain injury (mTBI)/concussion. Among them, rodent neurotrauma experiments have been most widely used, as transgenic and gene targeting technologies in mice allow us to test the roles of different genes in recovery from brain injury. Furthermore, the clinical relevance of rodent concussion studies can be improved by using these technologies to study concussions in animals that carry the human versions of genes known to play a role in neurological disease. However, delivering concussion injuries to the mice that are relevant to real-world human head impacts is challenging, as the mouse and human heads are dramatically different in shape and size. In the vast majority of mouse concussion experiments, the pathological and behavioral consequences of the injuries are evaluated without considering whether the injury model produces brain stretches (maximum principal strains) of the same magnitude as those experienced by human brains undergoing similar impacts. Methods We conducted a total of 201 computational simulations to understand both human and mouse brain strains that are directly linked to neuronal damage during closed-head concussive impacts. To represent real-world human head impacts we simulated mouse head impacts with durations of 1.5 ms (Type 1 scaling), followed by simulations with durations between 1 and 2 ms (Type 2), and finally, simulations with durations from 0.75 to 4.5 ms (Type 3) to develop scaling between human and mouse, as well as to reveal the predicted effects of small and large changes in impact durations on brain strain. Results Guided by these simulations we calculated that peak rotational velocities in mice could be achieved by scaling human peak rotational velocities with factors of 5.8, 4.6, and 6.8, for flexion/extension, lateral bending, and axial rotation, respectively, to reach equal brain strains between human and mouse. The effects of impact durations on scaling were also calculated and longer-duration mouse head impacts needed larger scaling factors to reach equal strain. Conclusions The scaling method will help us to create brain injury in the mouse with brain strain loading equivalent to those experienced in real-world human head impacts.

Head Impact Modeling to Support a Rotational Combat Helmet Drop Test

2021 ◽  
Author(s):  
Ryan Terpsma ◽  
Rika Wright Carlsen ◽  
Ron Szalkowski ◽  
Sushant Malave ◽  
Alice Lux Fawzi ◽  
...  
Keyword(s):  
Human Head ◽  
Mechanical Stimulus ◽  
Scientific Basis ◽  
Test Method ◽  
Drop Test ◽  
Head Impacts ◽  
Digital Twin ◽  
Brain Deformation ◽  
Acceleration Time Histories ◽  
Hybrid Iii

ABSTRACT Introduction The Advanced Combat Helmet (ACH) military specification (mil-spec) provides blunt impact acceleration criteria that must be met before use by the U.S. warfighter. The specification, which requires a helmeted magnesium Department of Transportation (DOT) headform to be dropped onto a steel hemispherical target, results in a translational headform impact response. Relative to translations, rotations of the head generate higher brain tissue strains. Excessive strain has been implicated as a mechanical stimulus leading to traumatic brain injury (TBI). We hypothesized that the linear constrained drop test method of the ACH specification underreports the potential for TBI. Materials and Methods To establish a baseline of translational acceleration time histories, we conducted linear constrained drop tests based on the ACH specification and then performed simulations of the same to verify agreement between experiment and simulation. We then produced a high-fidelity human head digital twin and verified that biological tissue responses matched experimental results. Next, we altered the ACH experimental configuration to use a helmeted Hybrid III headform, a freefall cradle, and an inclined anvil target. This new, modified configuration allowed both a translational and a rotational headform response. We applied this experimental rotation response to the skull of our human digital twin and compared brain deformation relative to the translational baseline. Results The modified configuration produced brain strains that were 4.3 times the brain strains from the linear constrained configuration. Conclusions We provide a scientific basis to motivate revision of the ACH mil-spec to include a rotational component, which would enhance the test’s relevance to TBI arising from severe head impacts.

Examining the interrelatedness between ontologies and Linked Data

2017 ◽  
Vol 35 (2) ◽  
pp. 312-331 ◽  
Author(s):  
Biswanath Dutta
Keyword(s):  
Real World ◽  
Linked Data ◽  
Current Work ◽  
Successful Implementation ◽  
World Systems ◽  
Ongoing Research ◽  
Content Type ◽  
Web Technologies ◽  
The One ◽  
Practical Implications

Purpose Ontology and Linked Data (LD) are the two prominent web technologies that have emerged in the recent past. Both of them are at the center of Semantic Web and its applications. Researchers and developers from both academia and business are actively working in these areas. The increasing interest in these technologies promoted the growth of LD sets and ontologies on the web. The purpose of this paper is to investigate the possible relationships between them. The effort is to investigate the possible roles that ontologies may play in further empowering the LD. In a similar fashion, the author also studies the possible roles that LD may play to empower ontologies. Design/methodology/approach The work is mainly carried out by exploring the ontology- and LD-based real-world systems, and by reviewing the existing literature. Findings The current work reveals, in general, that both the technologies are interdependent and have lots to offer to each other for their faster growth and meaningful development. Specifically, anything that we can do with LD, we can do more by adding an ontology to it. Practical implications The author envisions that the current work, in the one hand, will help in boosting the successful implementation and the delivery of semantic applications; on the other hand, it will also become a food for the future researchers in further investigating the relationships between the ontologies and LD. Originality/value So far, as per the author’s knowledge, there are very little works that have attempted in exploring the relationships between the ontologies and LD. In this work, the author illustrates the real-world systems that are based on ontology and LD, discusses the issues and challenges and finally illustrates their interdependency discussing some of the ongoing research works.

Comparison of Human Surrogate Responses in Underbody Blast Loading Conditions

2020 ◽  
Vol 142 (9) ◽  
Author(s):  
K. Ott ◽  
D. Drewry ◽  
M. Luongo ◽  
J. Andrist ◽  
R. Armiger ◽  
...  
Keyword(s):  
Vertical Direction ◽  
Whole Body ◽  
Matched Pair ◽  
Loading Conditions ◽  
Occupant Safety ◽  
Vertical Loading ◽  
Impact Biomechanics ◽  
Biomechanical Response ◽  
Hybrid Iii

Abstract Impact biomechanics research in occupant safety predominantly focuses on the effects of loads applied to human subjects during automotive collisions. Characterization of the biomechanical response under such loading conditions is an active and important area of investigation. However, critical knowledge gaps remain in our understanding of human biomechanical response and injury tolerance under vertically accelerated loading conditions experienced due to underbody blast (UBB) events. This knowledge gap is reflected in anthropomorphic test devices (ATDs) used to assess occupant safety. Experiments are needed to characterize biomechanical response under UBB relevant loading conditions. Matched pair experiments in which an existing ATD is evaluated in the same conditions as a post mortem human subject (PMHS) may be utilized to evaluate biofidelity and injury prediction capabilities, as well as ATD durability, under vertical loading. To characterize whole body response in the vertical direction, six whole body PMHS tests were completed under two vertical loading conditions. A series of 50th percentile hybrid III ATD tests were completed under the same conditions. Ability of the hybrid III to represent the PMHS response was evaluated using a standard evaluation metric. Tibial accelerations were comparable in both response shape and magnitude, while other sensor locations had large variations in response. Posttest inspection of the hybrid III revealed damage to the pelvis foam and skin, which resulted in large variations in pelvis response. This work provides an initial characterization of the response of the seated hybrid III ATD and PMHS under high rate vertical accelerative loading.

scholarly journals The Effects of Curtain Airbag on Occupant Kinematics and Injury Index in Rollover Crash

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Hongyun Li ◽  
Chengyue Jiang ◽  
Dong Cui ◽  
Shuang Lu
Keyword(s):  
Restraint System ◽  
Head Acceleration ◽  
Physical Test ◽  
Injury Index ◽  
Hybrid Iii ◽  
Protection Area ◽  
Occupant Injuries ◽  
Occupant Kinematics ◽  
Head And Neck Injury ◽  
Rollover Crash

Background. Occupant injuries in rollover crashes are associated with vehicle structural performance, as well as the restraint system design. For a better understanding of the occupant kinematics and injury index in certain rollover crash, it is essential to carry out dynamic vehicle rollover simulation with dummy included. Objective. This study focused on effects of curtain airbag (CAB) parameters on occupant kinematics and injury indexes in a rollover crash. Besides, optimized parameters of the CAB were proposed for the purpose of decreasing the occupant injuries in such rollover scenario. Method and Material. The vehicle motion from the physical test was introduced as the input for the numerical simulation, and the 50% Hybrid III dummy model from the MADYMO database was imported into a simulation model. The restraint system, including a validated CAB module, was introduced for occupant kinematics simulation and injury evaluation. TTF setting, maximum inflator pressure, and protection area of the CAB were analysed. Results. After introducing the curtain airbag, the maximum head acceleration was reduced from 91.60 g to 49.52 g, and the neck Mx and neck Fz were reduced significantly. Among these CAB parameters, the TTF setting had the largest effect on the head acceleration which could reduce 8.6 g furthermore after optimization. The neck Fz was decreased from 3766.48 N to 2571.77 N after optimization of CAB protection area. Conclusions. Avoiding hard contact is critical for the occupant protection in the rollover crashes. The simulation results indicated that occupant kinematics and certain injury indexes were improved with the help of CAB in such rollover scenario. Appropriate TTF setting and inflator selection could benefit occupant kinematics and injury indexes. Besides, it was advised to optimize the curtain airbag thickness around the head contact area to improve head and neck injury indexes.

scholarly journals Crashworthiness of vehicle-to-pole collisions using a hybrid III 3-year-old child dummy

2021 ◽  
Author(s):  
Vid Krznaric
Keyword(s):  
Causes Of Death ◽  
Motor Vehicle ◽  
Motor Vehicle Crashes ◽  
Neck Injuries ◽  
Child Injuries ◽  
Soil Systems ◽  
Hybrid Iii ◽  
Child Restraint ◽  
Protection Devices ◽  
Energy Absorbing

To date, statistics indicate that motor vehicle crashes are one of the leading causes of death and injury for children despite improved crashworthiness of vehicles and child restraint systems, since children are at risk for devastating head and neck injuries due to their fragile physiology. Thus, this thesis focused on minimizing child injuries experienced during frontal vehicle-to-pole collisions by improving on the safety and energy absorption of existing traffic pole structures. A finite element computer model, using LS-DYNA software, was used to simulate crash events in order to determine the influence of pole structural and material characteristics on the injury parameters of a 3-year-old child dummy occupant. It was concluded that the anchored base support, and the embedded pole in soil systems provide desirable crashworthy results. In addition, it is recommended to mandate traffic protection devices in all areas with poor energy absorbing characteristics that resemble non-deformable objects.

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