Interaction of external head impact parameters on region and volume of strain for collisions in sport

2018 ◽  
Vol 233 (2) ◽  
pp. 258-267 ◽  
Author(s):  
R Anna Oeur ◽  
Michael D Gilchrist ◽  
Thomas Blaine Hoshizaki
Keyword(s):  
Brain Injuries ◽  
Element Model ◽  
Brain Regions ◽  
Peak Strain ◽  
Centre Of Gravity ◽  
Impact Parameters ◽  
Four Levels ◽  
Set Up ◽  
The Impact ◽  
Strain Responses

Collisions with the head are the primary cause of concussion in contact sports. Head impacts can be further characterized by velocity, striking mass, compliance, and location (direction). The purpose of this study was to describe the interaction effects of these parameters on peak strain in four brain regions and the volume of strain for collision impacts. A pendulum test set-up was used to deliver impacts to an adult Hybrid III headform according to four levels of mass (3, 9, 15, and 21 kg), four velocities (1.5, 3.0, 4.5, and 6.0 m/s), two impact locations (through the centre of gravity and a non-centre of gravity), and three levels of compliance simulating unprotected, helmeted, and well-padded conditions in sport. Headform accelerations were input into a brain finite element model to obtain peak strain in the frontal, temporal, parietal, and occipital lobes and the volume of the brain experiencing 0.10, 0.15, 0.20, and 0.25 strains. Centre-of-gravity impacts created the highest strains (peak and volume) under low compliance and non-centre-of-gravity impacts produced greater strain responses under medium and high compliance conditions. The temporal lobe was the region that consistently displayed the highest peak strains, which may be due to the proximity of the impact locations to this region. Interactions between mass and velocity displayed effects where the 9-kg mass had higher peak and volumes of strain than the 15-kg mass at velocities of 3.0 and 4.5 m/s. This study demonstrates the important role of interacting impact parameters on increasing strain responses that are relevant to the spectrum of diffuse brain injuries, including concussion.

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 Implementation of a TMS-fMRI system: A primer

2021 ◽  
Author(s):  
Golnoush Alamian ◽  
Ruiyang Ge ◽  
Erin L. MacMillan ◽  
Laura Barlow ◽  
Afifa Humaira ◽  
...  
Keyword(s):  
Network Connectivity ◽  
Brain Regions ◽  
Pharmacological Intervention ◽  
University Of British Columbia ◽  
Functional Images ◽  
Fluctuation Noise ◽  
Spatial Noise ◽  
Set Up ◽  
The Impact

Transcranial magnetic stimulation (TMS) is a non-invasive and non-pharmacological intervention, approved for the treatment of individuals diagnosed with treatment-resistant depression. This well-tolerated approach uses magnetic pulses to stimulate specific brain regions and induce changes in brain networks at multiple levels of human functioning. Combining TMS with other neuroimaging techniques, such as functional magnetic resonance imaging (fMRI), offers new insights into brain functioning, and allows to map out the causal alterations brought on by TMS interventions on neural network connectivity and behaviour. However, the implemention of concurrent TMS-fMRI brings on a number of technical challenges that must be overcome to ensure good quality of functional images. The goal of this study was thus to investigate the impact of TMS pulses in an MR-environment on the quality of BRAINO phantom images, in terms of the signal of the images, the temporal fluctuation noise, the spatial noise and the signal to fluctuation noise ratio, at the University of British Columbia (UBC) Neuroimaging facility. The results of our analyses replicated those of previous sites, and showed that the present set-up for concurrent TMS-fMRI ensures minimal noise artefact on functional images obtained through this multimodal approach. This step was a key stepping stone for future clinical trials at UBC.

scholarly journals Characterization and Imaging of Localized Thickness Loss in GFRP with Ka-Band Microwave Open-Ended Waveguides

2020 ◽  
Author(s):  
Jinhua Hu ◽  
Yong Li ◽  
Jianguo Tan ◽  
Wenjia Li ◽  
Zhenmao Chen
Keyword(s):  
Ultrasonic Testing ◽  
Impact Damage ◽  
Element Model ◽  
Fibre Reinforcement ◽  
Destructive Testing ◽  
Ka Band ◽  
Thickness Loss ◽  
Set Up ◽  
The Impact ◽  
Non Destructive

Glass Fibre Reinforcement Plastic (GFRP) is widely used in engineering fields including aerospace, marine and construction, etc. During practical service, it is prone to the impact damage leading to the Localized Thickness Loss (LTL) which severely influences the integrity and safety of GFRP. To detect and evaluate LTL in GFRP, common Non-Destructive Testing (NDT) techniques such as ultrasonic testing and thermography are usually applied. Complementary to these methods, microwave NDT has been found to be one of the promising techniques in quantitative evaluation of GFRP. In this paper, the characterization and imaging of LTL in GFRP by microwave NDT are intensively investigated. A 2D Finite Element Model (FEM) with the Ka-band open-ended waveguide and GFRP sample subject to LTL has been set up and adopted for analysis of field characteristics and testing signals. Following that, an experimental investigation is conducted to further study the feasibility of LTL imaging by microwave NDT with the Ka-band open-ended waveguide. The results from simulations and experiments indicate the applicability of Ka-band microwave open-ended waveguide for detection and evaluation of LTL in GFRP.

scholarly journals Approaches for Monitoring Warfighter Blast-related Exposures in Training to Develop Effective Safety Standards

2021 ◽  
Vol 186 (Supplement_1) ◽  
pp. 515-522
Author(s):  
Steven Kornguth ◽  
Henry G Rylander ◽  
Spencer Smith ◽  
Julia Campbell ◽  
Steve Steffensen ◽  
...  
Keyword(s):  
Auditory Cortex ◽  
Brain Injuries ◽  
New Technologies ◽  
Technical Information ◽  
Brain Regions ◽  
Auditory Evoked Potential ◽  
Safety Standards ◽  
Early Signs ◽  
Rapid Deceleration ◽  
The Impact

ABSTRACT Introduction Traumatic brain injuries are of concern to the sports and military communities because of the age of the participants and costly burden to society. To markedly reduce the impact of traumatic brain injury and its sequela (TBI-S), it is necessary to determine the initial vulnerability of individuals as well as identify new technologies that indicate early signs of TBI-S. Materials and Methods Currently, diverse methods have been used by the authors and others in laboratory settings to reveal early signs of persistent TBI-S including simulation modeling of the effect of rapid deceleration on the deviatoric strain (shear force) imposed on specific brain regions, auditory evoked potential (AEP) measurements to determine injury to the auditory cortex optokinetic nystagmus (OKN) measures sensitive to vestibular trauma, and optical coherence tomography (OCT) measures that reveal changes in central visual function obtained noninvasively by examination of the retina. Results Simulation studies provided technical information on maximal deviatoric strain at the base of the sulci and interface of gray and white matter consistent with results from neuropathology and from magnetic resonance imaging. The AEP and OKN reveal measurable injury to similar regions below the Sylvian fissure including auditory cortex and midbrain, and the OCT reveals changes to the retina consistent with forceful deceleration effects. Conclusions The studies and results are consistent with prior work demonstrating that noninvasive tests may be sensitive to the presence of TBI-S, potentially in the training field as advances in the portability of test instruments are underway. When combined with baseline data gathered from individuals in quantitative form, key variances can emerge. Therefore, it is hypothesized that AEP, OKN, and OCT, taken together, may yield faster objective and quantitative neurophysiological measures serving as a “signature” of neural injury and more indicative of potentially persistent TBI-S—recommending larger scale longitudinal studies.

The Fractional Diagnosis of Multi-Span Continuous Bridge’s Structural Damage Based on Neural Network and Genetic Algorithm

2011 ◽  
Vol 71-78 ◽  
pp. 1298-1304 ◽  
Author(s):  
Shun Guo Li ◽  
Hui Li
Keyword(s):  
Structural Damage ◽  
Traffic Accidents ◽  
Damage Index ◽  
Element Model ◽  
Bridge Engineering ◽  
Bridge Structure ◽  
Concrete Carbonation ◽  
Detection Approach ◽  
Set Up ◽  
The Impact

The natural environmental erosion and human factors such as the impact of traffic accidents, crack propagation, concrete carbonation and etc, make the bridge’s damage more serious. Therefore, the bridge damage diagnosis has become a hot field of bridge engineering issues. This paper put forward the fractional diagnosis method of multi-span bridge structure reflecting the structural cracks and carbonation damage. In this paper, adopting the optimization equivalent method, the finite element model of damaged structure is set up according to the damaging characteristic of multi-span continuous bridge structure. A damage index of strain mode with practical meanings is adopted which can reflect local damage. Basing on this index, fractional-step detection method of structural damage is presented. The first step is to identify the damage region, then locate the detailed damage location and degree; Performance of the proposed damage detection approach is demonstrated with analysis of a multi-span continuous bridge. The result turns up trumps.

Traumatic Events in Human Head: Biomechanical Insight by Means of a Finite Element Model

2006 ◽  
Author(s):  
Giovanni Belingardi ◽  
Giorgio Chiandussi ◽  
Ivan Gaviglio
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Finite Element Model ◽  
Brain Injuries ◽  
Head Injuries ◽  
Traumatic Events ◽  
Traumatic Injury ◽  
Human Head ◽  
Element Model ◽  
The Impact

Head injuries due to traumatic events in case of head impact are one of the main causes of death or permanent invalidity in vehicle crash. The main purpose of the present work is to evaluate pressure and stress distributions in bones and brain tissues of a human head due to an impact by means of numerical simulations. Pressures and stresses in the different zones of the head can be related to the main brain injuries as verified by head traumatology doctors. The availability of a numerical model of head allows to quantify the relationship between type and intensity of the impact and the possible head injury. This capability represents a relevant step torward an effective traumatic injury prevention. The proposed numerical model is quite complex although some simplifications have been introduced like modeling all the inner organs as a continuum without sliding interfaces or fluid elements. Geometrical characteristics for the finite element model have been extracted from CT (Computer Tomography) and MRI (Magnetic Resonance Image) scanner images, while material mechanical characteristics have been taken from literature. The model has been validated by comparing the numerical results and the experimental results from literature. The protecting action of the ventricles and of several membranes (dura mater, tentorium and falx) has been evaluated.

Analysis on Galloping Responses of Transmission Tower-Line System

2014 ◽  
Vol 602-605 ◽  
pp. 3025-3028
Author(s):  
Yu Xian Di ◽  
Kuan Jun Zhu ◽  
Bin Liu ◽  
Long Liu ◽  
Cao Lan Liu
Keyword(s):  
Element Model ◽  
Linear Increase ◽  
Nonlinear Finite Element ◽  
System Model ◽  
Transmission Tower ◽  
Ansys Software ◽  
Line System ◽  
Set Up ◽  
Nonlinear Finite Element Model ◽  
The Impact

Nonlinear finite element model of a transmission tower-line system was set up and galloping of iced bundle conductors in the system was numerically simulated by means of ANSYS software. Based on galloping trajectories, vibration frequency, galloping order, conductor tension; unbalanced tension characteristics of iced conductors, it was shown that values of the conductor amplitudes by the tower-line system model are increased by 20% compared to the conductor model. The values of the strain tower unbalanced tensions by the tower-line system model are decreased by 20% and the values of the suspension tower unbalanced tensions by the tower-line system model are decreased by 62.5% compared to the conductor model conductor-insulator mode1. The galloping order is different for different span, due to the impact of the order of galloping. The amplitude of the vertical galloping is increasing while the increasing span, but it is not linear increase.

MOTIF DAN DAMPAK PERNIKAHAN DINI DI INDARUNG NGALAU BATU GADANG

2018 ◽  
Vol 1 (1) ◽  
pp. 1
Author(s):  
Murisal Murisal
Keyword(s):  
Young Men ◽  
Early Marriage ◽  
Marriage Law ◽  
Men And Women ◽  
Home Life ◽  
Family Household ◽  
Set Up ◽  
The Impact ◽  
Husband And Wife

Motif and Impact of Early Marriage in Indarung Ngalau Batu Gadang.Penelitian is motivated by teenagers who married early on. Today, young men and women have a tendency to be less prepared to enter the home life, they are only ready to marry (ready here can be interpreted, maturity in terms of financial, understand what the meaning of marriage according to marriage law) is the bond of inner birth between a man and a woman as husband and wife for the purpose of forming a happy and eternal family (household) based on the Supreme Godhead while they are not ready to set up a home, whereas to build a household requires preparation both physically and spiritually . The purpose of this study to determine the motives underlying adolescents to make early marriage and the impact caused in the household as a result of the marriage.

Dissent and Education

2018 ◽  
Author(s):  
Mark Burden
Keyword(s):  
Eighteenth Century ◽  
Seventeenth Century ◽  
Educational Activity ◽  
Educational Institutions ◽  
Higher Educational Institutions ◽  
Legal Restrictions ◽  
Higher Educational ◽  
Set Up ◽  
The Impact ◽  
Dissenting Academies

Much eighteenth-century Dissenting educational activity was built on an older tradition of Puritan endeavour. In the middle of the seventeenth century, the godly had seen education as an important tool in spreading their ideas but, in the aftermath of the Restoration, had found themselves increasingly excluded from universities and schools. Consequently, Dissenters began to develop their own higher educational institutions (in the shape of Dissenting academies) and also began to set up their own schools. While the enforcement of some of the legal restrictions that made it difficult for Dissenting institutions diminished across the eighteenth century, the restrictions did not disappear entirely. While there has been considerable focus on Dissenting academies and their contribution to debates about doctrinal orthodoxy, the impact of Dissenting schools was also considerable.

scholarly journals On Kaufmann's theory of the impact of the pianoforte hammer

1920 ◽  
Vol 97 (682) ◽  
pp. 99-110 ◽  
Keyword(s):  
Initial Conditions ◽  
Practical Importance ◽  
Prima Facie ◽  
Point Of View ◽  
Infinite Length ◽  
Modes Of Vibration ◽  
Rigorous Treatment ◽  
The Subject ◽  
Set Up ◽  
The Impact

The theory of the vibrations of the pianoforte string put forward by Kaufmann in a well-known paper has figured prominently in recent discussions on the acoustics of this instrument. It proceeds on lines radically different from those adopted by Helmholtz in his classical treatment of the subject. While recognising that the elasticity of the pianoforte hammer is not a negligible factor, Kaufmann set out to simplify the mathematical analysis by ignoring its effect altogether, and treating the hammer as a particle possessing only inertia without spring. The motion of the string following the impact of the hammer is found from the initial conditions and from the functional solutions of the equation of wave-propagation on the string. On this basis he gave a rigorous treatment of two cases: (1) a particle impinging on a stretched string of infinite length, and (2) a particle impinging on the centre of a finite string, neither of which cases is of much interest from an acoustical point of view. The case of practical importance treated by him is that in which a particle impinges on the string near one end. For this case, he gave only an approximate theory from which the duration of contact, the motion of the point struck, and the form of the vibration-curves for various points of the string could be found. There can be no doubt of the importance of Kaufmann’s work, and it naturally becomes necessary to extend and revise his theory in various directions. In several respects, the theory awaits fuller development, especially as regards the harmonic analysis of the modes of vibration set up by impact, and the detailed discussion of the influence of the elasticity of the hammer and of varying velocities of impact. Apart from these points, the question arises whether the approximate method used by Kaufmann is sufficiently accurate for practical purposes, and whether it may be regarded as applicable when, as in the pianoforte, the point struck is distant one-eighth or one-ninth of the length of the string from one end. Kaufmann’s treatment is practically based on the assumption that the part of the string between the end and the point struck remains straight as long as the hammer and string remain in contact. Primâ facie , it is clear that this assumption would introduce error when the part of the string under reference is an appreciable fraction of the whole. For the effect of the impact would obviously be to excite the vibrations of this portion of the string, which continue so long as the hammer is in contact, and would also influence the mode of vibration of the string as a whole when the hammer loses contact. A mathematical theory which is not subject to this error, and which is applicable for any position of the striking point, thus seems called for.

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