Finite-Element-Based Transfer Equations: Post-Mortem Human Subjects versus Hybrid III Test Dummy in Frontal Sled Impact

2015 ◽  
Vol 3 (1) ◽  
pp. 57-80
Author(s):  
Raed E. El-jawahri ◽  
Tony R. Laituri ◽  
Agnes S. Kim ◽  
Stephen W. Rouhana ◽  
Para V. Weerappuli
Keyword(s):  
Finite Element ◽  
Human Subjects ◽  
Post Mortem ◽  
Transfer Equations ◽  
Hybrid Iii

Finite-Element-Based Transfer Equations: Post-Mortem Human Subjects versus Hybrid III Test Dummy in Blunt Impact

2014 ◽  
Vol 2 (1) ◽  
pp. 117-129 ◽  
Author(s):  
Raed E. El-jawahri ◽  
Tony R. Laituri ◽  
Agnes S. Kim ◽  
Stephen W. Rouhana ◽  
Para V. Weerappuli
Keyword(s):  
Finite Element ◽  
Human Subjects ◽  
Post Mortem ◽  
Blunt Impact ◽  
Transfer Equations ◽  
Hybrid Iii

Level- and Region-Specific Properties of Young Human Lumbar Annulus

2011 ◽  
Author(s):  
Brian D. Stemper ◽  
Narayan Yoganandan ◽  
Barry S. Shender ◽  
Glenn R. Paskoff ◽  
Frank A. Pintar ◽  
...  
Keyword(s):  
Finite Element ◽  
Material Properties ◽  
Human Subjects ◽  
Statistical Significance ◽  
Finite Element Models ◽  
Post Mortem ◽  
Spinal Level ◽  
Lumbar Intervertebral Disc ◽  
Internal Load ◽  
Anatomical Region

The objective of this study was to determine the material properties of the human lumbar intervertebral disc annulus as a function of anatomical region and spinal level. Samples from minimally or nondegenerated spines were extracted from young post mortem human subjects and tested in tension. Statistically significant differences were found based on anatomical region. Trends appear to indicate spinal level dependency, although additional samples are required to attain statistical significance. It is possible to use finite element models incorporating these region- and level-specific properties to quantify internal load-sharing and delineate the mechanism of disorders such as herniation.

Tissue necrosis and passage of fluid due to cold stress from the thermally damaged human body peripherals: A mathematical model

2015 ◽  
Vol 04 (02) ◽  
pp. 1550012
Author(s):  
M. A. Khanday ◽  
Fida Hussain ◽  
Khalid Nazir
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Heat Equation ◽  
Cold Stress ◽  
Human Body ◽  
Human Subjects ◽  
Diffusion Equations ◽  
Tissue Necrosis ◽  
Cold Temperatures ◽  
Element Technique

The development of cold injury takes place in the human subjects by means of crystallization of tissues in the exposed regions at severe cold temperatures. The process together with the evaluation of the passage of fluid discharge from the necrotic regions with respect to various degrees of frostbites has been carried out by using variational finite element technique. The model is based on the Pennes' bio-heat equation and mass diffusion equations together with suitable initial and boundary conditions. The results are analyzed in relation with atmospheric temperatures and other parameters of the tissue medium.

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.

Multidirection Validation of a Finite Element 50th Percentile Male Hybrid III Anthropomorphic Test Device for Spaceflight Applications

2019 ◽  
Vol 141 (3) ◽  
Author(s):  
Derek A. Jones ◽  
James P. Gaewsky ◽  
Mona Saffarzadeh ◽  
Jacob B. Putnam ◽  
Ashley A. Weaver ◽  
...  
Keyword(s):  
Finite Element ◽  
Injury Risk ◽  
Fe Model ◽  
Fe Modeling ◽  
Test Device ◽  
Qualitative And Quantitative ◽  
Hybrid Iii ◽  
Physical Tests ◽  
Quantitative Results ◽  
Male Hybrid

The use of anthropomorphic test devices (ATDs) for calculating injury risk of occupants in spaceflight scenarios is crucial for ensuring the safety of crewmembers. Finite element (FE) modeling of ATDs reduces cost and time in the design process. The objective of this study was to validate a Hybrid III ATD FE model using a multidirection test matrix for future spaceflight configurations. Twenty-five Hybrid III physical tests were simulated using a 50th percentile male Hybrid III FE model. The sled acceleration pulses were approximately half-sine shaped, and can be described as a combination of peak acceleration and time to reach peak (rise time). The range of peak accelerations was 10–20 G, and the rise times were 30–110 ms. Test directions were frontal (−GX), rear (GX), vertical (GZ), and lateral (GY). Simulation responses were compared to physical tests using the correlation and analysis (CORA) method. Correlations were very good to excellent and the order of best average response by direction was −GX (0.916±0.054), GZ (0.841±0.117), GX (0.792±0.145), and finally GY (0.775±0.078). Qualitative and quantitative results demonstrated the model replicated the physical ATD well and can be used for future spaceflight configuration modeling and simulation.

scholarly journals Factors Affecting the Severity of Placental Abruption in Pregnant Vehicle Drivers: Analysis with a Novel Finite Element Model

Healthcare ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 27
Author(s):  
Katsunori Tanaka ◽  
Yasuki Motozawa ◽  
Kentaro Takahashi ◽  
Tetsuo Maki ◽  
Masahito Hitosugi
Keyword(s):  
Finite Element ◽  
Pregnant Woman ◽  
Finite Element Model ◽  
Placental Abruption ◽  
Motor Vehicle ◽  
Human Subjects ◽  
Element Model ◽  
Collision Velocity ◽  
Vehicle Collisions ◽  
Factors Affecting

We clarified factors affecting the severity of placental abruption in motor vehicle collisions by quantitively analyzing the area of placental abruption in a numerical simulation of an unrestrained pregnant vehicle driver at collision velocities of 3 and 6 m/s. For the simulation, we constructed a novel finite element model of a small 30-week pregnant woman, which was validated anthropometrically using computed tomography data and biomechanically using previous examinations of post-mortem human subjects. In the simulation, stress in the elements of the utero–placental interface was computed, and those elements exceeding a failure criterion were considered to be abrupted. It was found that a doubling of the collision velocity increased the area of placental abruption 10-fold, and the abruption area was approximately 20% for a collision velocity of 6 m/s, which is lower than the speed limit for general roads. This result implies that even low-speed vehicle collisions have negative maternal and fetal outcomes owing to placental abruption without a seatbelt restraint. Additionally, contact to the abdomen, 30 mm below the umbilicus, led to a larger placental abruption area than contact at the umbilicus level when the placenta was located at the uterus fundus. The results support that a reduction in the collision speed and seatbelt restraint at a suitable position are important to decrease the placental abruption area and therefore protect a pregnant woman and her fetus in a motor vehicle collision.

Finite element comparison of human and Hybrid III responses in a frontal impact

2015 ◽  
Vol 85 ◽  
pp. 125-156 ◽  
Author(s):  
Kerry A. Danelson ◽  
Adam J. Golman ◽  
Andrew R. Kemper ◽  
F. Scott Gayzik ◽  
H. Clay Gabler ◽  
...  
Keyword(s):  
Finite Element ◽  
Frontal Impact ◽  
Hybrid Iii
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