MECHANISM OF SENSORINEURAL HEARING LOSS CAUSED BY TYPICAL SCLEROSIS OF COCHLEA

2021 ◽  
Author(s):  
ZHENGSHAN ZHAO ◽  
WENJUAN YAO ◽  
JIAKUN WANG ◽  
LEI ZHOU ◽  
XINSHENG HUANG
Keyword(s):  
Hearing Loss ◽  
Clinical Medicine ◽  
Three Dimensional ◽  
Element Model ◽  
3D Fem ◽  
Sensory Structure ◽  
Ethical Problems ◽  
Biomechanical Behavior ◽  
Alternative Research ◽  
Human Ear

It is difficult to measure the cochlea directly because of the ethical problems and the complexity of cochlear structure. Therefore, finite element model (FEM) can be used as an effective alternative research method. An accurate FEM of the human ear can not only help people understand the mechanisms of sound transmission, but also effectively assess the effects of otologic diseases and guide research on the treatment of hearing loss. In this paper, a three-dimensional (3D) FEM of the human normal cochlea is proposed to study the changes in the biomechanical behavior of the cochlear sensory structure caused by the anterior fissure sclerosis and bottom-turn and apex-turn ossification of the cochlear window. The degree and harm of hearing loss caused by diseases are quantitatively predicted, which can deepen the understanding of the biomechanical mechanism of cochlea, and provide theoretical basis for clinical medicine.

3D Fem Study of Fluid Flow in the Mould for Billet Continuous Casting

2009 ◽  
Vol 79-82 ◽  
pp. 1269-1272
Author(s):  
Wei Chen ◽  
Bao Xiang Wang ◽  
Yu Zhu Zhang ◽  
Jin Hong Ma ◽  
Su Juan Yuan
Keyword(s):  
Fluid Flow ◽  
Continuous Casting ◽  
Casting Speed ◽  
Three Dimensional ◽  
Casting Process ◽  
Element Model ◽  
3D Fem ◽  
Billet Continuous Casting ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

In this paper, a three-dimensional finite element model is developed to simulate and analyze the turbulent flow in the mould of billet continuous casting. The result shows that if the SEN is used in the continuous casting process, there exists a symmetrical stronger vortex in the middle of the mould and a weaker vortex above the nozzle. The casting speed, the depth and diameter of SEN all have significant effect on the fluid flow field and the turbulent kinetic energy on the meniscus, and then have effect on the billet quality. At the given conditions, the optimum set of parameters is: the casting speed 0.035 , the depth of the SEN 0.1 , the diameter of the SEN 0.025 . Online verifying of this model has been developed, which can be proved that it is very useful to control the steel quality and improve the productivity.

Analytical Simulations of the Steel-Laminated Elastomeric Bridge Bearing

2014 ◽  
Vol 30 (4) ◽  
pp. 373-382 ◽  
Author(s):  
R.-Z. Wang ◽  
S.-K. Chen ◽  
K.-Y. Liu ◽  
C.-Y. Wang ◽  
K.-C. Chang ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Fem Analysis ◽  
Material Model ◽  
Element Model ◽  
Test Results ◽  
3D Fem ◽  
Contact Algorithm ◽  
Elastomeric Bearing ◽  
Nonlinear Responses ◽  
Bridge Bearing

AbstractIn this paper, analytical simulations of the steel-laminated elastomeric bearing (SLEB) using a three-dimensional (3D) finite element model incorporating material, geometric nonlinearities, and a frictional contact algorithm in LS-DYNA code is conducted. In order to simulate the nonlinear responses of the elastomeric bearing under the compression and shear, a hyperviscoelastic rubber model such as The MAT_77_H (MAT_HYPERVISCOELASTIC_RUBBER) in LS- DYNA code is adopted. Based on the proposed material model for the SLEB, the interaction effects of the SLEB under compression, bending, and torsion are analyzed. Analytical results are compared with the test results of the SLEBs. A set of material parameters is proposed for 3D FEM analysis of SLEBs. The proposed material model demonstrates its accuracy.

CONSTRUCTION AND VALIDATION OF A THREE-DIMENSIONAL FINITE ELEMENT MODEL OF THE DISTAL RADIOULNAR JOINT

2016 ◽  
Vol 16 (02) ◽  
pp. 1650010
Author(s):  
JIANWEI SUN ◽  
BINGSHAN YAN ◽  
WENZHONG NIE ◽  
ZHONGZHENG ZHI ◽  
KEKE GUI ◽  
...  
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Distal Radioulnar Joint ◽  
3D Fem ◽  
Compression Load ◽  
Radioulnar Joint ◽  
Bending Load ◽  
Simulation Results ◽  
Load Conditions

Objectives: The study was to establish a precise three-dimensional (3D) finite element model (FEM) of the distal radioulnar joint (DRUJ) and then to validate its accuracy for the application to the research on clinical biomechanics. Materials and methods: The right forearm DRUJ of a volunteer (male, 28 years old, 62 kilograms) was scanned by computed tomography (CT) and magnetic resonance imaging (MRI). The resulting sectional images were input into MIMICS10.1 and ANSYS10.0 to generate 3D FEM of the DRUJ. With this FEM, the bending load, axial compression load and the torsion load conditions were simulated, and the vonmises stress distribution of the DRUJ was detected. The simulation results were compared with the biomechanics experiment results which were reported by the literatures. Results: The constructed FEM consisted of 333,805 elements and 508,384 nodes. Together, the simulation results with this FEM were in consistent with those of the reported experiments in bending load, axial compression load and torsion load conditions. Discussion: The 3D FEM of the DRUJ can reflect the real geometric structure of the DRUJ objectively and the simulation with this FEM can predict the results of the biomechanics experiments successfully.

Three-Dimensional Nonlinear Finite Element Model for Simulating Pavement Response: Study at Canterbury Accelerated Pavement Testing Indoor Facility, New Zealand

2003 ◽  
Vol 1823 (1) ◽  
pp. 153-162 ◽  
Author(s):  
Mofreh F. Saleh ◽  
Bruce Steven ◽  
David Alabaster
Keyword(s):  
Finite Element ◽  
New Zealand ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
Nonlinear Finite Element ◽  
3D Fem ◽  
Accelerated Pavement Testing ◽  
Pavement Testing ◽  
Nonlinear Finite Element Model

A three-dimensional nonlinear finite element model (3D-FEM) was developed as part of a study of the effect of increasing axle load and tire pressure on pavement deterioration. The measured strains, interface stresses, and deflections were collected from the instrumented Canterbury Accelerated Pavement Testing Indoor Facility in New Zealand. In addition, two multilayer elastic models were used to compare the values from the finite element simulation and the actual measurements. The first elastic multilayer model was developed with ELSYM5 software, and the second model was developed with CIRCLY software. CIRCLY differs from ELSYM5 in the ability to account for material anisotropy; ELSYM5 considers the pavement materials to be isotropic. The actual strains and deformations were measured by Emu strain gauges embedded at different depths in the base and subgrade materials. Both the unbound granular base and the subgrade materials were modeled in 3D-FEM as elastic plastic materials. The results showed that for the unbound base layer, the strains calculated from the two elastic models were in reasonable agreement with the values measured in the instrumented test track, while the 3D-FEM model tended to overestimate the strains at the bottom of the base. While none of the models provided a perfect fit to the measured strains in the subgrade layer because the subgrade is less homogenous than assumed, 3D-FEM provided the closest fit. Also, CIRCLY provided better results than ELSYM5, which underestimated the displacement values compared with values obtained with CIRCLY and 3D-FEM.

Optimization of a Steam Turbine Blade’s Double-T Root Through Contact Surface Convexity

2016 ◽  
Author(s):  
Johanna Ehlers ◽  
Henning Ressing ◽  
Wulf-Christof von Karstedt ◽  
Daniel Rixen ◽  
Mohamed S. Gadala
Keyword(s):  
Steam Turbine ◽  
Turbine Blade ◽  
Contact Surface ◽  
Three Dimensional ◽  
Peak Stress ◽  
Element Model ◽  
Von Mises Stress ◽  
3D Fem ◽  
Fem Model ◽  
Von Mises

The turbine blade is one of the most critical components of a steam turbine. The high thermal loads and large centrifugal forces cause extreme stresses on the blade, especially on its root. This paper focuses on improving the double-T root of a turbine blade of the control stage by decreasing the root’s peak equivalent von-Mises stress. An 18% reduction was achieved in the peak stress by changing the convexity of the contact surface between the root and the groove. The equivalent von-Mises stress was determined in a static structural analysis of a three dimensional finite element model (3D FEM-model) using ANSYS Workbench. This numerical model was developed to include one blade and the associated part of the shaft, whereas the complete circle of blades was considered by applying cyclic symmetry. Furthermore, this paper includes a modal analysis comparing the natural frequencies of the initial FEM-model with the frequencies of the optimized one. The results were established by an investigation of the influence of the FEM-model’s parameters, its material properties, thermal effects, and an additional damping wire in the shroud.

scholarly journals Biomechanical behavior of indirect composite materials: a 3D-FEA study

2017 ◽  
Vol 20 (3) ◽  
Author(s):  
João Paulo Mendes Tribst ◽  
Amanda Maria de Oliveira Dal Piva ◽  
Alexandre Luis Souto Borges
Keyword(s):  
Elastic Modulus ◽  
External Surface ◽  
Three Dimensional ◽  
Element Model ◽  
Composite Resins ◽  
Principal Stresses ◽  
Finite Elements Analysis ◽  
Biomechanical Behavior ◽  
3D Fea ◽  
Indirect Composite

<p><strong>Objective:</strong> This study aimed to evaluate the influence of the elastic modulus of indirect composite resins (ICR) in the stress distribution of a restored maxillary first premolar. <strong>Material and methods:</strong> A three-dimensional (3D) finite element model of the tooth and the mesial-occlusal-distal (MOD) restoration was created. Three ICR were simulated, by changing the elastic modulus: 10, 15 and 20 GPa. All materials were considered as isotropic, homogeneous and linearly elastic. An occlusal load (200 N) was applied on occlusal surface trough a sphere, and the nodes of the external surface of the root were fixed.  The maximum principal stresses on the tooth and restoration were analyzed. <strong>Results:</strong> According to FE analysis, the lower the ICR elastic modulus, the higher the stress values generated on the remaining tooth. For the restoration, the opposite was observed: the lower the modulus, the lower the stress. <strong>Conclusion:</strong> With the limitations of this study <span style="text-decoration: underline;">it </span>is possible to conclude that the greater the elastic modulus of the restorative material the harder it will be to deflect the cusps, but the easier the fracture of the resin.</p><p><strong>Keywords: </strong>Finite Elements Analysis; Composite Resin; Indirect Restoration; Flexural Strength.</p>

The Construction of Three-Dimensional Finite Element Model of TKA Knee

2013 ◽  
Vol 681 ◽  
pp. 319-323
Author(s):  
Bin Jiang ◽  
Yue Fu Dong ◽  
Yang Hu ◽  
Qing Rong Xu ◽  
Guang Hong Hu
Keyword(s):  
3D Model ◽  
Knee Prosthesis ◽  
Three Dimensional ◽  
Image Data ◽  
Element Model ◽  
Collateral Ligaments ◽  
Total Knee Prosthesis ◽  
3D Fem ◽  
Total Knee ◽  
Mri Image

The goal of this study is to construct a three-dimensional (3D) finite element model (FEM) of total knee arthroplasty (TKA) knee including bones, collateral ligaments and total knee prosthesis. Computed tomography (CT) and magnetic resonance imaging (MRI) image data of normal knee joint are imported into MIMICS software. The 3D models of bones and collateral ligaments are respectively reconstructed from CT and MRI image data. Then the reconstructed models are registered and fused together based on external landmarks. The virtual osteotomy and total knee prosthesis implantation are performed to establish the 3D model of TKA knee. Ultimately, A elaborate 3D FEM of TKA knee including anatomical structures and total knee prosthesis is obtained by meshing the 3D model of TKA knee and setting material properties, loading and boundary conditions. The obtained von Mises stress on the polyethlene insert confirms to the clincial mechanical distribution characteristics after TKA. The 3D FEM of TKA knee retains the integrity and accuracy in the anatomical features and provides a foundation for accurate research on the TKA knee biomechanical behaviors.

scholarly journals Implant Treatment in Atrophic Maxilla by Titanium Hybrid-Plates: A Finite Element Study to Evaluate the Biomechanical Behavior of Plates

Metals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 573
Author(s):  
María Prados-Privado ◽  
Henri Diederich ◽  
Juan Prados-Frutos
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Clinical Results ◽  
Principal Stresses ◽  
Biomechanical Behavior ◽  
Osseointegrated Implants ◽  
Atrophic Maxilla ◽  
Cumulative Function ◽  
Von Mises

A severely atrophied maxilla presents serious limitations for rehabilitation with osseointegrated implants. This study evaluated the biomechanical and long-term behavior of titanium hybrid-plates in atrophic maxilla rehabilitation with finite elements and probabilistic methodology. A three-dimensional finite element model based on a real clinical case was built to simulate an entirely edentulous maxilla with four plates. Each plate was deformed to become accustomed to the maxilla’s curvature. An axial force of 100 N was applied in the area where the prosthesis was adjusted in each plate. The von Mises stresses were obtained on the plates and principal stresses on maxilla. The difference in stress between the right and left HENGG-1 plates was 3%, while between the two HENGG-2 plates it was 2%, where HENGG means Highly Efficient No Graft Gear. A mean maximum value of 80 MPa in the plates’ region was obtained, which is a lower value than bone resorption stress. A probability cumulative function was computed. Mean fatigue life was 1,819,235 cycles. According to the results of this study, it was possible to conclude that this technique based on titanium hybrid-plates can be considered a viable alternative for atrophic maxilla rehabilitation, although more studies are necessary to corroborate the clinical results.

Torsional Analysis of a Steel Cord-Rubber Tire Belt Structure

1996 ◽  
Vol 24 (4) ◽  
pp. 339-348 ◽  
Author(s):  
R. M. V. Pidaparti
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Composite Structures ◽  
Three Dimensional ◽  
Element Model ◽  
Torsional Stiffness ◽  
Element Analysis ◽  
Rubber Belt ◽  
Steel Cord ◽  
Torsional Analysis

Abstract A three-dimensional (3D) beam finite element model was developed to investigate the torsional stiffness of a twisted steel-reinforced cord-rubber belt structure. The present 3D beam element takes into account the coupled extension, bending, and twisting deformations characteristic of the complex behavior of cord-rubber composite structures. The extension-twisting coupling due to the twisted nature of the cords was also considered in the finite element model. The results of torsional stiffness obtained from the finite element analysis for twisted cords and the two-ply steel cord-rubber belt structure are compared to the experimental data and other alternate solutions available in the literature. The effects of cord orientation, anisotropy, and rubber core surrounding the twisted cords on the torsional stiffness properties are presented and discussed.

Finite Element Analysis of Nonuniformity of Tires with Imperfections5

2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Radial Force ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Force Variation ◽  
Three Dimensional Finite Element

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.

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