scholarly journals Study on Behind Helmet Blunt Trauma Caused by High-Speed Bullet

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Zhihua Cai ◽  
Xingyuan Huang ◽  
Yun Xia ◽  
Guibing Li ◽  
Zhuangqing Fan
Keyword(s):  
Brain Tissue ◽  
Blunt Trauma ◽  
Dura Mater ◽  
High Speed ◽  
Optimization Design ◽  
Reference Value ◽  
Element Model ◽  
Impact Speed ◽  
The Impact ◽  
The Brain

The mechanism of Behind Helmet Blunt Trauma (BHBT) caused by a high-speed bullet is difficult to understand. At present, there is still a lack of corresponding parameters and test methods to evaluate this damage effectively. The purpose of the current study is therefore to investigate the response of the human skull and brain tissue under the loading of a bullet impacting a bullet-proof helmet, with the effects of impact direction, impact speed, and impactor structure being considered. A human brain finite element model which can accurately reconstruct the anatomical structures of the scalp, skull, brain tissue, etc., and can realistically reflect the biomechanical response of the brain under high impact speed was employed in this study. The responses of Back Face Deformation (BFD), brain displacement, skull stress, and dura mater pressure were extracted from simulations as the parameters reflecting BHBT risk, and the relationships between BHBT and bullet-proof equipment structure and performance were also investigated. The simulation results show that the frontal impact of the skull produces the largest amount of BFD, and when the impact directions are from the side, the skull stress is about twice higher than other directions. As the impact velocity increases, BFD, brain displacement, skull stress, and dura mater pressure increase. The brain damage caused by different structural bullet bodies is different under the condition of the same kinetic energy. The skull stress caused by the handgun bullet is the largest. The findings indicate that when a bullet impacts on the bullet-proof helmet, it has a higher probability of causing brain displacement and intracranial high pressure. The research results can provide a reference value for helmet optimization design and antielasticity evaluation and provide the theoretical basis for protection and rescue.

Analysis of Sports Related mTBI Injuries Caused by Elastic Wave Propagation Through Brain Tissue

2014 ◽  
Author(s):  
David Case ◽  
Edmond Richer
Keyword(s):  
Brain Tissue ◽  
Neurological Disorders ◽  
Human Head ◽  
Element Model ◽  
Pressure Gradients ◽  
Young Athletes ◽  
The World ◽  
Propagation Of Waves ◽  
The Impact ◽  
The Brain

Repetitive concussions and sub-concussions suffered by athletes have been linked to a series of sequelae ranging from traumatic encephalopathy to dementia pugilistica. We developed a detailed finite element model of the human head based on standard libraries of medical imaging. The model includes realistic material properties of the brain tissue, bone, soft tissue, and cerebral spinal fluid, as well as a helmet. The strains/stresses and pressure gradients and concentrations created in the brain tissue due to propagation of waves produced by the impact through the complex internal structure of the human head for various impact scenarios were studied. This approach has the potential to expand our understanding of the mechanism of brain injury, and to better assessment of risk of delayed neurological disorders for tens of thousands of young athletes throughout the world.

High-speed impacts of slender bodies into non-smooth, complex fluids

2018 ◽  
Vol 861 ◽  
Author(s):  
Ishan Sharma
Keyword(s):  
Penetration Depth ◽  
High Speed ◽  
Complex Fluids ◽  
Laboratory Data ◽  
Impact Speed ◽  
High Speed Impact ◽  
Smooth Complex ◽  
Theoretical Predictions ◽  
Slender Bodies ◽  
The Impact

We present a simple hydrodynamical model for the high-speed impact of slender bodies into frictional geomaterials such as soils and clays. We model these materials as non-smooth, complex fluids. Our model predicts the evolution of the impactor’s speed and the final penetration depth given the initial impact speed, and the material and geometric parameters of the impactor and the impacted material. As an application, we investigate the impact of deep-penetrating anchors into seabeds. Our theoretical predictions are found to match field and laboratory data very well.

Optimization Design of DVG850 Worktable System Based on ANSYS Workbench

2012 ◽  
Vol 184-185 ◽  
pp. 356-359
Author(s):  
Jiang Miao Yi ◽  
Dong Qiang Gao ◽  
Fei Zhang ◽  
Huan Lin
Keyword(s):  
Modal Analysis ◽  
Natural Frequency ◽  
High Speed ◽  
Optimization Design ◽  
Element Model ◽  
Single Screw ◽  
Machining Center ◽  
The Finite Element Model ◽  
Better Than ◽  
Ansys Workbench

The finite element model of worktable system is created and modal analysis is made with ANSYS Workbench by taking DVG850 high-speed vertical machining center worktable system for example. We make modal analysis of single-screw strength general reinforcement worktable system and get the natural frequency and the vibration mode.Then in order to improve the system's natural frequency, the scheme of dual-screw worktable system is put forward. Also natural frequency and vibration mode is got. Finally, it is proved that the performance of dual-screw worktable system is significantly better than the single-screw one. This provides a reliable reference for further study on dynamic analysis of worktable system.

The Design and Finite Element Analysis for Crane Turntable Gear Based on Pro/E and ANSYS

2013 ◽  
Vol 710 ◽  
pp. 243-246
Author(s):  
Xian Hong Yang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Product Design ◽  
Optimization Design ◽  
Three Dimensional ◽  
Reference Value ◽  
Element Model ◽  
Helical Gear ◽  
Engineering Analysis ◽  
Element Analysis

The use of Pro/E and their respective advantages ANSYS software product design and engineering analysis to solve the case, first of all in the Pro/E, the completion of three-dimensional helical gear design, and then in the Pro/MECHANICA completed finite element model of helical gear, and then into ANSYS for finite element analysis of bevel gear calculation and simulation, finite element analysis of the final results of optimization design model is presented recommendations for improvement. The product design and engineering analysis method has some reference value in engineering design.

Biomechanical Comparison of Real World Concussive Impacts in Children, Adolescents, and Adults

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Lauren Dawson ◽  
David Koncan ◽  
Andrew Post ◽  
Roger Zemek ◽  
Michael D. Gilchrist ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Brain Tissue ◽  
Dynamic Models ◽  
Element Model ◽  
Tissue Response ◽  
Model Simulations ◽  
Child Group ◽  
Adolescents And Adults ◽  
The Impact

Abstract Accidental falls occur to people of all ages, with some resulting in concussive injury. At present, it is unknown whether children and adolescents are at a comparable risk of sustaining a concussion compared to adults. This study reconstructed the impact kinematics of concussive falls for children, adolescents, and adults and simulated the associated brain tissue deformations. Patients included in this study were diagnosed with a concussion as defined by the Zurich Consensus guidelines. Eleven child, 10 adolescent, and 11 adult falls were simulated using mathematical dynamic models(MADYMO), with three ellipsoid pedestrian models sized to each age group. Laboratory impact reconstruction was conducted using Hybrid III head forms, with finite element model simulations of the brain tissue response using recorded impact kinematics from the reconstructions. The results of the child group showed lower responses than the adolescent group for impact variables of impact velocity, peak linear acceleration, and peak rotational acceleration but no statistical differences existed for any other groups. Finite element model simulations showed the child group to have lower strain values than both the adolescent and adult groups. There were no statistical differences between the adolescent and adult groups for any variables examined in this study. With the cases included in this study, young children sustained concussive injuries at lower modeled brain strains than adolescents and adults, supporting the theory that children may be more susceptible to concussive impacts than adolescents or adults.

scholarly journals Research on Blade-Casing Rub-Impact Mechanism by Experiment and Simulation in Aeroengines

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Jie Hong ◽  
Tianrang Li ◽  
Zhichao Liang ◽  
Dayi Zhang ◽  
Yanhong Ma
Keyword(s):  
High Speed ◽  
High Performance ◽  
Element Model ◽  
Physical Parameters ◽  
Test Rig ◽  
Calculation Results ◽  
Rotor Support ◽  
Blade Tip ◽  
Set Up ◽  
The Impact

Aeroengines pursue high performance, and compressing blade-casing clearance has become one of the main ways to improve turbomachinery efficiency. Rub-impact faults occur frequently with clearance decreasing. A high-speed rotor-support-casing test rig was set up, and the mechanism tests of light and heavy rub-impact were carried out. A finite element model of the test rig was established, and the calculation results were in good agreement with the experimental results under both kinds of rub-impact conditions. Based on the actual blade-casing structure model, the effects of the major physical parameters including imbalance and material characteristics were investigated. During the rub-impact, the highest stress occurs at the blade tip first and then it is transmitted to the blade root. Deformation on the impact blade tip generates easily with decreased yield strength, and stress concentration at the blade tip occurs obviously with weaker stiffness. The agreement of the computation results with the experimental data indicates the method could be used to estimate rub-impact characteristics and is effective in design and analyses process.

scholarly journals Chemerin-induced macrophages pyroptosis in fetal brain tissue leads to cognitive disorder in offspring of diabetic dams

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Zhaoxia Liang ◽  
Luyang Han ◽  
Dianjianyi Sun ◽  
Yanmin Chen ◽  
Qi Wu ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Brain Tissue ◽  
Abdominal Cavity ◽  
Behavioral Changes ◽  
Dependent Manner ◽  
Diabetes In Pregnancy ◽  
The Impact ◽  
The Brain ◽  
In Pregnancy ◽  
Brain Tissues

Abstract Background Chemerin is highly expressed in the serum, placenta tissue, and umbilical cord blood of diabetic mother; however, the impact of chemerin on cognitive disorders of offspring from mothers with diabetes in pregnancy remains unclear. Methods A diabetic phenotype in pregnant mice dams was induced by streptozocin (STZ) injection or intraperitoneal injection of chemerin. Behavioral changes in offspring of diabetic dams and nondiabetic controls were assessed, and changes in chemerin, two receptors of chemerin [chemerin receptor 23 (ChemR23) and chemokine (C-C motif) receptor-like 2 (CCRL2)], macrophages, and neurons in the brain tissue were studied to reveal the underlying mechanism of the behavioral changes. Results Chemerin treatment mimicked the STZ-induced symptom of maternal diabetes in mice along with the altered behavior of offspring in the open field test (OFT) assay. In the exploring process for potential mechanism, the brain tissues of offspring from chemerin-treated dams were observed with an increase level of macrophage infiltration and a decrease number of neuron cells. Moreover, an increased level of NOD-like receptor family pyrin domain containing 3 (NLRP3) and apoptosis-associated speck-like (Asc) protein as well as pyroptosis [characterized by increased active caspase-1 content and secretion of cytokines such as interleukin (IL) 1 beta (IL-1β) and IL-18] more activated in macrophages is also observed in the brain of these diabetic dam’s offspring, in the presence of ChemR23. In vitro, it was found that pyroptosis activation was increased in macrophages separated from the abdominal cavity of normal mice, after chemerin treatment. However, depletion of CCRL2 decreased the level of chemerin in the brain tissues of diabetic dams’ offspring; depletion of ChemR23 decreased macrophage pyroptosis, and depletion of either receptor reversed chemerin-mediated neurodevelopmental deficits and cognitive impairment of offspring of diabetic pregnant dams. Conclusions Chemerin induced diabetic pregnant disease and CCRL2 were required to enrich chemerin in the brain of offspring. Aggregation of chemerin could lead to macrophage recruitment, activation of pyroptosis, the release of inflammatory cytokines, a decrease in the number of neurons, and cognitive impairment in offspring in a ChemR23-dependent manner. Targeting CCRL2 and/or ChemR23 could be useful for treating neuropsychological deficits in offspring of dams with diabetes in pregnancy.

Interfacial Heat Transfer During Droplet Impact on a Solid Surface: Comparison of High-Resolution Laser Measurements With Finite-Element Simulations

2007 ◽  
Author(s):  
Rajneesh Bhardwaj ◽  
Jon P. Longtin ◽  
Daniel Attinger
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Finite Element ◽  
High Speed ◽  
Element Model ◽  
Deposition Process ◽  
Interfacial Heat Transfer Coefficient ◽  
Interfacial Heat Transfer ◽  
Laser Measurements ◽  
The Impact

The objective of this work is to understand the coupling of fluid dynamics and heat transfer during the impact of a millimeter-size water droplet on a flat, solid glass substrate. In this work, a finite-element model is presented which simulates the transient fluid dynamics and heat transfer during the droplet deposition process, considering Laplace forces on the liquid-gas boundary, and the dynamics of wetting. A novel, experimental laser-based method is used to measure temperatures at the solid-liquid interface. This method is based on a thermoreflectance technique and provides unprecedented temporal and spatial resolutions of 1 microsecond and 20 micrometer, respectively. Matching between simulations, temperature measurements and high-speed visualization allows the determination of the interfacial heat transfer coefficient.

scholarly journals Effect of hemostasis and electrosurgery on the development and evolution of brain tumor surgery in the late 19th and early 20th centuries

2005 ◽  
Vol 18 (4) ◽  
pp. 1-7 ◽  
Author(s):  
John R. Vender ◽  
Jason Miller ◽  
Andy Rekito ◽  
Dennis E. McDonnell
Keyword(s):  
Brain Tumor ◽  
Brain Tissue ◽  
Surgical Management ◽  
Tumor Surgery ◽  
Brain Tumor Surgery ◽  
The Impact ◽  
Neurological Surgeon ◽  
The Brain ◽  
Development And Evolution ◽  
Type Of Surgery

Hemostatic options available to the surgeon in the late 19th and early 20th centuries were limited. The surgical ligature was limited in value to the neurological surgeon because of the unique structural composition of brain tissue as well as the approaches and operating angles used in this type of surgery. In this manuscript the authors review the options available and the evolution of surgical hemostatic techniques and electrosurgery in the late 19th and early 20th centuries and the impact of these methods on the surgical management of tumors of the brain and its coverings.

The Efficacy of Impact-Absorbing Materials during Collision with a Soccer Ball

2013 ◽  
Vol 440 ◽  
pp. 363-368
Author(s):  
Zahari Taha ◽  
Mohd Hasnun Arif Hassan ◽  
Mohd Azri Aris
Keyword(s):  
High Speed ◽  
Impact Force ◽  
Coefficient Of Restitution ◽  
Soccer Ball ◽  
Absorbing Materials ◽  
The Subject ◽  
The Impact ◽  
The Brain ◽  
Peak Impact Force ◽  
Impact Duration

The uniqueness of soccer is that the players are allowed to use their head to pass the ball to a teammate of even try to score goal. Studies have shown that heading in soccer might be dangerous to the brain and could lead to brain trauma. There are headgears available for soccer players to protect their head, but studies have proven that currently available headgears are ineffective in reducing the impact caused by a soccer ball. The objective of this study is to test the efficacy of six different types of impact-absorbing materials in reducing the linear impact force from a soccer ball. The soccer ball was dropped from the height of 2.3 m onto a force platform to measure the impact force. A high-speed camera is used to record the motion and the impact duration, and then the coefficient of restitution for each impact was determined. Polyurethane (PU) comb-gel was found to be the most effective material in reducing the peak impact force and impulse compared with other materials. The reduction in peak force was associated with longer impact duration between the soccer ball and the PU comb-gel. However, the coefficient of restitution was reduced by 21.7%, implying that using the gel alone will reduce the speed of the ball after heading, thus reducing the performance of a player wearing it. A combination of PU gel and another stiffer material is suggested and the effectiveness of the composite will be the subject of future investigation.

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