Vocal Fold Dynamics During Phonations

Author(s):  
H. Lan ◽  
A. M. Al-Jumaily ◽  
A. Mirnajafi

During phonation, the vocal folds collision in the glottal closure is considered as a risk factor for pathology development. Based on the finite element model using the software ABAQUS™, the impact stresses between the vocal folds are studied.

Author(s):  
L. Hai ◽  
A. M. Al-Jumaily ◽  
A. Mirnajafi

The vibration characteristics of the vocal folds are investigated using a finite element model which incorporates the in-homogeneity and anisotropy of the materials and the irregularity of the geometry. The model employs the cover and body theory to build the structure of the vocal folds and implements measured viscoelastic properties of the mucosa and the transverse isotropic elastic properties of the muscles. It has the potential to simulate some vocal-fold disorders and determine the change in characteristics. To determine the oscillation characteristics of the folds, the eigenfrequency and eigenmodes of the finite element model are determined using the ABAQUS software. The model results compare well with some experiments performed on a silicon vocal fold. It is anticipated that the model will help to identify voice disorders such as vocal-fold paralysis and vocal-fold nodules.


2014 ◽  
Vol 577 ◽  
pp. 310-313
Author(s):  
Ping Yang ◽  
Zhou De Qu ◽  
Min Li

Based on the impact of some horizontal filtering tank’s instability in operation process on production, the present paper discusses the optimal design scheme for horizontal filtering tank structure with the help of finite element. Theoretical guidance will be given to enterprise from the perspective of finite element for the purpose of improving the horizontal filtering tank through constructing the finite element model for horizontal filtering tank with Creo parametric software, conducting simulation with workbench software[1] and finally arriving at the reasonable design scheme after analysis, thus avoiding the structural instability caused by the over-constraint of structural leg support beam and filter plate under-constraint.


2019 ◽  
Vol 9 (13) ◽  
pp. 2735 ◽  
Author(s):  
Paul J. Hadwin ◽  
Mohsen Motie-Shirazi ◽  
Byron D. Erath ◽  
Sean D. Peterson

Bayesian estimation has been previously demonstrated as a viable method for developing subject-specific vocal fold models from observations of the glottal area waveform. These prior efforts, however, have been restricted to lumped-element fitting models and synthetic observation data. The indirect relationship between the lumped-element parameters and physical tissue properties renders extracting the latter from the former difficult. Herein we propose a finite element fitting model, which treats the vocal folds as a viscoelastic deformable body comprised of three layers. Using the glottal area waveforms generated by self-oscillating silicone vocal folds we directly estimate the elastic moduli, density, and other material properties of the silicone folds using a Bayesian importance sampling approach. Estimated material properties agree with the “ground truth” experimental values to within 3 % for most parameters. By considering cases with varying subglottal pressure and medial compression we demonstrate that the finite element model coupled with Bayesian estimation is sufficiently sensitive to distinguish between experimental configurations. Additional information not available experimentally, namely, contact pressures, are extracted from the developed finite element models. The contact pressures are found to increase with medial compression and subglottal pressure, in agreement with expectation.


Author(s):  
Tom Allen ◽  
James Ibbitson ◽  
Steve Haake

Oblique impacts between a ball and surface are a key part of many sports. Previous work has shown that a ball can slide, over-spin or roll at the end of an impact, depending on impact conditions. Inbound spin ratio was analysed to determine if it could be used to identify what is likely to happen at the end of impact for all sports regardless of surface, ball type, impact velocity, angle and spin. A predictive model, in the form of a finite element model, of a tennis ball was validated against experimental data for oblique impacts with inbound spin ratios in the range of –1 to 1. Spin ratio is defined as the product of the ball’s angular velocity and radius divided by the centre of mass velocity tangential to the surface. The finite element model was then used to determine the effect of impact conditions and ball parameters on outbound spin ratio. The study showed that for constant inbound spin ratio, outbound spin ratio was dependent on inbound velocity and angle. For constant inbound velocity and angle, decreasing the mass and increasing the stiffness of the ball through a change in material properties resulted in an increase in the maximum outbound spin ratio. Inbound spin ratio can be used to predict how a ball will rebound from a surface; however, inbound velocity and angle must be constant. Spin ratio can therefore be used to compare the impact characteristics for different ball and surface scenarios.


2005 ◽  
Vol 114 (11) ◽  
pp. 847-852 ◽  
Author(s):  
David A. Berry ◽  
Haven Reininger ◽  
Fariborz Alipour ◽  
Diane M. Bless ◽  
Charles N. Ford

Objectives: A systematic study of the influence of vocal fold scarring on phonation was conducted. In particular, phonatory variables such as fundamental frequency, oral acoustic intensity, and phonation threshold pressure (PTP) were investigated as a function of the size and position of the laryngeal scar. Methods: By means of a finite element model of vocal fold vibration, the viscoelastic properties of both normal and scarred vocal fold mucosae were simulated on the basis of recent rheological data obtained from rabbit and canine models. Results: The study showed that an increase in the viscoelasticity of the scarred mucosa resulted in an increase in fundamental frequency, an increase in PTP, and a decrease in oral acoustic intensity. With regard to positioning of the scar, the PTP increased most significantly when the scar was within ±2 mm of the superior-medial junction of the vocal folds. Conclusions: The systematic data obtained in this investigation agree with the general clinical experience. In the future, these findings may be further validated on human subjects as newly emerging technologies such as linear skin rheometry and optical coherence tomography allow the histologic and viscoelastic properties of the normal and scarred vocal fold mucosae to be measured in the clinic.


2020 ◽  
Vol 174 ◽  
pp. 01051
Author(s):  
Alexander Abramovich ◽  
Yuri Stepanov ◽  
Juraj Janocko

This article considers the prerequisites to the development of technologies and a method of computer analysis of the influence of the coal mining process on the state of the earth’s surface in the district of the breakage face. The paper presents an algorithm for the implementation of preparatory works for analysis of the influence of coal mining on the state of the earth’s surface in the district of the block in the form of activity diagram, as well as the tools that are necessary for this analysis are considered. The technologies of 3D modeling of massif by means of FreeCAD are considered, and the analysis of solids formation methods, characterizing rock formation, is carried out. For more accurate calculations and analysis, the finite element model of massif must be built with detail, that is, to break down solids into smaller elements. The article represents a technology, the application of which will be implemented in cooperation with rock geographic information systems, which be capable of a detail analysis and assessment of the impact of coal mining on the surface within the second working.


2010 ◽  
Vol 163-167 ◽  
pp. 2131-2136 ◽  
Author(s):  
Jian Bo Chen ◽  
Bao Dong Liu ◽  
Peng Fei Li

Based on Miyamoto’s method, the natural frequency of prestressed box girder with corrugated steel webs considering the impact of external tendons was obtained. And the result was modified based on the finite element model. It shows that: the external tendons will reduce the natural frequency of bridge with reduced range of about 3%. Beneficial references were provided to the layout of external tendons in order to avoid the resonance between the box girder with corrugated steel webs and the external tendons.


2012 ◽  
Vol 215-216 ◽  
pp. 1191-1196 ◽  
Author(s):  
Xiao Ming Yuan ◽  
Li Jie Zhang ◽  
Xin Ying Chen ◽  
Bing Du ◽  
Bao Hua Li ◽  
...  

In order to predict the result of impact test in the design phase and reduce the experimental times, which can save cost and shorten development cycle, a finite element model of aluminum alloy wheel 13-degree impact test is established based on Abaqus. All mechanical parts such as the standard impact block, the assembly of the wheel and the tire, the support and bolts are included in the finite element model. The predicted result of finite element analysis and the experimental result agree very well shows the finite element model is correct. The equivalent plastic strain value was also put forward as fracture criterion for the wheel in the impact test which realizes the transition from the qualitative analysis to the quantitative analysis in the development process of aluminum alloy wheel.


2012 ◽  
Vol 263-266 ◽  
pp. 3174-3176
Author(s):  
Qi Wang ◽  
Su Jiao Shi

An impact event is a complex phenomenon that includes the interaction between projectile and structure, motion of the projectile and the dynamics of the structure. Complete modeling of an impact event can always be done using a 3D finite element model, The Finite Element Model(FEM) approach is often very costly both from modeling and calculation duration point of views, so it can be simplified by using simplified impact models, It can be used for the estimation of the contact force history. In this paper, firstly, analyze the current situation of the study of the collision of the home and abroad , secondly, Ocean Bottom Seismometer(OBS) whereabouts and hit the bottom are analyzed in detail, and finally come to the impact solution formulas.


2018 ◽  
Vol 9 (4) ◽  
pp. 484-503 ◽  
Author(s):  
Luwei Chen ◽  
Hao Wu ◽  
Qin Fang ◽  
Tao Zhang

Accidents involving collisions of heavy-duty trucks with highway bridge piers occurred occasionally, in which the bridge piers might be subjected to severe damage, and cause the collapse of the superstructure due to the loss of axial loading capacity. The existing researches are mostly concentrated on the light- or medium-duty trucks. This article mainly concerns about the collisions between the heavy-duty trucks (e.g. tractor-trailer) and bridge piers as well as the evaluation of the impact force. First, by modifying the finite element model of Ford F800 single-unit truck, which was developed by National Crash Analysis Center, the finite element model of a tractor-trailer is established. Then, the full-scale tractor-trailer crash test on concrete-filled steel pier jointly conducted by Texas Transportation Institute, Federal Highway Administration, and Texas Department of Transportation is numerically simulated. The impact process is well reproduced and the established model is validated by comparison of the impact force. It indicates that the tractor-trailer impact force time history consists of two or three peaks and the corresponding causes are revealed. Furthermore, the parametric influences on the impact force are discussed, including the diameter and cross section shape of the pier, cargo weight, impact velocity, relative impact position, and vehicle type. Finally, the finite element model of an actual reinforced concrete highway bridge pier is established, and the impact force and lateral displacement of the pier subjected to the impact of the tractor-trailer are numerically derived and discussed.


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