Consequences of Viscoelastic Behavior in the Human Temporomandibular Joint Disc

2007 ◽  
Vol 86 (12) ◽  
pp. 1198-1202 ◽  
Author(s):  
J.H. Koolstra ◽  
T.M.G.J. van Eijden
Keyword(s):  
Temporomandibular Joint ◽  
Viscoelastic Behavior ◽  
Material Model ◽  
Von Mises Stress ◽  
Joint Movement ◽  
Temporomandibular Joint Disc ◽  
Apparent Stiffness ◽  
Linear Viscoelastic Material ◽  
Masticatory System ◽  
Von Mises

The consequences of the viscoelastic behavior of the temporomandibular joint disc were analyzed in simulated jaw open-close cycles. It was hypothesized that viscoelasticity helps protect the underlying bone, while augmenting the smoothness of articular movements. Simulations were performed with a dynamic model of the masticatory system, incorporating the joints’ cartilaginous structures as Finite Element Models. A non-linear viscoelastic material model was applied for the disc. The apparent stiffness of the disc to principal stress was largest when the jaw was closed, whereas, with the Von Mises’ stress, it appeared largest when the jaw was open. The apparent stiffnesses appeared to be dependent on both the speed of the movements and the presence of a resistance between the teeth. It was concluded that the disc becomes stiffer when load concentrations can be expected. During continued cyclic motion, it softens, which favors smoothness of joint movement at the cost of damage prevention.

scholarly journals Biomechanical Behavior of the Temporomandibular Joint Disc

2003 ◽  
Vol 14 (2) ◽  
pp. 138-150 ◽  
Author(s):  
Eiji Tanaka ◽  
Theo van Eijden
Keyword(s):  
Temporomandibular Joint ◽  
Viscoelastic Behavior ◽  
Collagen Fibers ◽  
Extrinsic Factors ◽  
Temporomandibular Joint Disc ◽  
Applied Loading ◽  
Biomechanical Behavior ◽  
Flow Through ◽  
The Difference ◽  
Fiber Mesh

The temporomandibular joint (TMJ) disc consists mainly of collagen fibers and proteoglycans constrained in the interstices of the collagen fiber mesh. This construction results in a viscoelastic response of the disc to loading and enables the disc to play an important role as a stress absorber during function. The viscoelastic properties depend on the direction (tension, compression, and shear) and the type of the applied loading (static and dynamic). The compressive elastic modulus of the disc is smaller than its tensile one because the elasticity of the disc is more dependent on the collagen fibers than on the proteoglycans. When dynamic loading occurs, the disc is likely to behave less stiffly than under static loading because of the difference of fluid flow through and out of the disc during loading. In addition, the mechanical properties change as a result of various intrinsic and extrinsic factors in life such as aging, trauma, and pathology. Information about the viscoelastic behavior of the disc is required for its function to be understood and, for instance, for a suitable TMJ replacement device to be constructed. In this review, the biomechanical behavior of the disc in response to different loading conditions is discussed.

scholarly journals Investigation on Microstructural Damage Properties of Asphalt Mixture Using Linear and Damage-Coupled Viscoelastic Model

2019 ◽  
Vol 9 (2) ◽  
pp. 303
Author(s):  
Wenke Huang ◽  
Zhibin Ren ◽  
Xiaoning Zhang ◽  
Jiangmiao Yu
Keyword(s):  
Stress Distribution ◽  
Viscoelastic Model ◽  
Asphalt Mixture ◽  
Viscoelastic Behavior ◽  
Von Mises Stress ◽  
Micromechanical Modeling ◽  
Fe Model ◽  
Asphalt Mastic ◽  
Simulation Results ◽  
Von Mises

This paper presents an image-based micromechanical modeling approach for simulating the damage-couple viscoelastic response of asphalt mixture. Details of the numerical damage-couple viscoelastic constitutive formulation implemented in a finite element code are presented and illustrated by using the ABAQUS user material subroutine (UMAT). Then, an experimental procedure based on the Linear Amplitude Sweep test for obtaining the viscoelastic and damage parameters at a given temperature was conducted. An improved morphological multi-scale algorithm was employed to segment the adhesive coarse aggregate images. We developed a pixel-based digital reconstruction model of asphalt mixture with the X-ray CT image after being processed. Finally, the image-based FE model incorporated with damage-coupled viscoelastic asphalt mastic phase and elastic aggregates was used for the compressive test simulations successfully in this study. Simulation results showed that the damaged simulation results have a larger stress distribution compared with the undamaged simulation due to the irregularity of the coarse aggregates. The von Mises stress distribution is smaller as the loading time increases due to the viscoelastic behavior of asphalt mastic. It can also provide insight on the damaged mechanisms and the possible location in asphalt mixture where microscopic cracking would most likely occur.

scholarly journals A Finite Element Modeling and Simulation of Human Temporomandibular Joint with and Without TM Disorders: An Indian Experience

2021 ◽  
Vol 8 (3) ◽  
pp. 347-355
Author(s):  
Mehak Sharma ◽  
Manoj Soni
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Temporomandibular Joint ◽  
Computational Study ◽  
3D Models ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Stress Studies ◽  
Jaw Joint ◽  
Von Mises

Temporomandibular joint (TMJ) is anatomically the most intricate joint which connects the lower jaw to the upper jaw and regulates jaw movements. It significantly deals with mastication and speech. It is hence imperative to study the mechanics and functioning of the jaw joint to devise alternative solutions for its replacement whenever required. Further, human skulls are anthropologically categorized into three types – African, Asian and European. Out of these, the Indian skull is also a bit different than its Asian counterparts because of its osteology and skeletal biology. Hence, a comprehensive biomechanical and computational study is essential to provide customized solutions. For the present study, four different loading conditions are selected to perform finite element analysis on the human skull, Anonymized and unidentifiable CT scan data sets from open-source web platforms are converted to STL and then 3D models using 3D slicer. Finite element analysis of jaw joint is carried out. Results based on Von Mises stress studies show significant behavioral differences under varying load conditions. Hence, it is crucial to identify solutions for TMJ disorders of the Indian population.

scholarly journals Biological Treatments for Temporomandibular Joint Disc Disorders: Strategies in Tissue Engineering

Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 933
Author(s):  
Daniela Trindade ◽  
Rachel Cordeiro ◽  
Henrique Cardoso José ◽  
David Faustino Ângelo ◽  
Nuno Alves ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Temporomandibular Joint ◽  
Total Disc Replacement ◽  
Special Focus ◽  
Temporomandibular Joint Disc ◽  
Complete Knowledge ◽  
Masticatory System ◽  
Materials Used ◽  
Important Structure

The temporomandibular joint (TMJ) is an important structure for the masticatory system and the pathologies associated with it affect a large part of the population and impair people’s lifestyle. It comprises an articular disc, that presents low regeneration capacities and the existing clinical options for repairing it are not effective. This way, it is imperative to achieve a permanent solution to guarantee a good quality of life for people who suffer from these pathologies. Complete knowledge of the unique characteristics of the disc will make it easier to achieve a successful tissue engineering (TE) construct. Thus, the search for an effective, safe and lasting solution has already started, including materials that replace the disc, is currently growing. The search for a solution based on TE approaches, which involve regenerating the disc. The present work revises the TMJ disc characteristics and its associated diseases. The different materials used for a total disc replacement are presented, highlighting the TE area. A special focus on future trends in the field and part of the solution for the TMJ problems described in this review will involve the development of a promising engineered disc approach through the use of decellularized extracellular matrices.

scholarly journals Effect of Impact and Bearing Parameters on Bird Strike with Aero-Engine Fan Blades

2021 ◽  
Vol 12 (1) ◽  
pp. 7
Author(s):  
Bin Wu ◽  
Reza Hedayati ◽  
Zhehua Li ◽  
Mahsa Aghajanpour ◽  
Guichang Zhang ◽  
...  
Keyword(s):  
Material Model ◽  
Von Mises Stress ◽  
Economic Losses ◽  
Bird Strike ◽  
Impact Location ◽  
Aero Engine ◽  
Particle Hydrodynamics ◽  
Bird Impact ◽  
Von Mises ◽  
The Impact

Bird strikes are one major accident for aircraft engines and can inflict heavy casualties and economic losses. In this study, a smoothed particle hydrodynamics (SPH) mallard model has been used to simulate bird impact to rotary aero-engine fan blades. The simulations were performed using the finite element method (FEM) at LS-DYNA. The reliability of the material model and numerical method was verified by comparing the numerical results with Wilberk’s experimental results. The effects of impact and bearing parameters, including bird impact location, bird impact orientation, initial bird velocity, fan rotational speeds, stiffness of the bearing, and the damping of the bearing on the bird impact to aero-engine fan blade are studied and discussed. The results show that both the impact location and bird orientation have significant effects on the bird strike results. Bird impact to blade roots is the most dangerous scenario causing the impact force to reach 390 kN. The most dangerous orientation is the case where the bird’s head is tilted 45° horizontally, which leads to huge fan kinetic energy loss as high as 64.73 kJ. The bird’s initial velocity affects blade deformations. The von Mises stress during the bird strike process can reach 1238 MPa for an initial bird velocity of 225 m/s. The fan’s rotational speed and the bearing stiffness affect the rotor stability significantly. The value of bearing damping has little effect on the bird strike process. This paper gives an idea of how to evaluate the strength of fan blades in the design period.

Nonlinear Analysis of Bioprosthetic Heart Valves under Dynamic Loading

2012 ◽  
Vol 152-154 ◽  
pp. 732-736
Author(s):  
Quan Yuan ◽  
Xin Ye ◽  
Hai Bo Ma ◽  
Hua Cong ◽  
Xu Huang
Keyword(s):  
Heart Valve ◽  
Heart Valves ◽  
Material Model ◽  
Von Mises Stress ◽  
Stress Distributions ◽  
Bioprosthetic Heart Valve ◽  
Element Analysis ◽  
Bioprosthetic Heart Valves ◽  
Diastolic Phase ◽  
Von Mises

In order to investigate the effect of material nonlinearity on the dynamic behavior of bioprosthetic heart valve, we establish the spherical, cylindrical and ellipsoidal leaflets models with the material model of Mooney-Rivlin. The mechanical behavior of bioprosthetic valve leaflet during diastolic phase is analyzed. The finite element analysis results show that the stress distributions of the ellipsoidal and spherical valve leaflets are comparatively reasonable. The ellipsoidal and spherical valve leaflets have the following advantages over the cylindrical leaflet valve, lower peak von-Mises stress, smaller stress concentration area, and relatively uniform stress distribution. This work is very helpful to manufacture reasonable shaped valvular leaflets，thus to prolong the lifetime of the bioprosthetic heart valve.

scholarly journals Investigation on the Thermoforming of Pmsq-Hdpe for the Manufacture of a NACA Profile of Small Dimensions

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1622
Author(s):  
Erchiqui Fouad ◽  
Abdessamad Baatti ◽  
Karima Ben Hamou ◽  
Hamid Kaddami ◽  
Mhamed Souli ◽  
...  
Keyword(s):  
Viscoelastic Behavior ◽  
Von Mises Stress ◽  
Integral Model ◽  
Aviation Industry ◽  
Element Formulation ◽  
Closed Volume ◽  
External Work ◽  
Combination Process ◽  
New Family ◽  
Von Mises

Unmanned aerial vehicles (UAVs) or drones are attracting increasing interest in the aviation industry, both for military and civilian applications. The materials used so far in the manufacture of UAVs are wood, plastic, aluminum and carbon fiber. In this regard, a new family of high-density polyethylene (HDPE) nanocomposites reinforced with polymethylsilsesquioxane nanoparticles (PMSQ), with mechanical performances significantly superior to those of pure HPDE, has been prepared by a fusion-combination process. Their viscoelastic properties were determined by oscillatory shear tests and their viscoelastic behavior characterized by the Lodge integral model. Then, the Lagrangian formulation and the membrane theory assumption were used in the explicit implementation of the dynamic finite element formulation. For the forming phase, we considered the thermodynamic approach to express the external work in terms of closed volume. In terms of von Mises stress distribution and thickness in the blade, the results indicate that HDPE-PMSQ behaves like virgin HDPE. Furthermore, its materials, for all intents and purposes, require the same amount of energy to form as HDPE.

DYNAMIC STRESS DISTRIBUTION IN A MODEL OF IMPLANTED MANDIBLE: NUMERICAL ANALYSIS OF VISCOELASTIC BONE

2015 ◽  
Vol 15 (04) ◽  
pp. 1550050 ◽  
Author(s):  
H. MOTALLEBZADEH ◽  
M. TAFAZZOLI-SHADPOUR ◽  
M. M. KHANI
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Cortical Bone ◽  
Dynamic Loading ◽  
Viscoelastic Behavior ◽  
Element Model ◽  
Von Mises Stress ◽  
Dental Implantation ◽  
Trabecular Bones ◽  
Von Mises

To determine the success of dental implants, mechanical stress distribution in the implant-bone interface is considered to be a determinant. Many researchers have used finite element modeling of implant-bone through applying static loading on the implant; however, dynamic loading has not extensively been investigated specially considering viscoelastic behavior of the bone. The aim of this study is to analyze effects of viscoelasticity of bone and dynamic loading comparable to mastication conditions on stress distribution in an implanted mandible. A three-dimensional finite-element model of an implanted mandible in the first molar region was constructed from computerized tomography data. Effects of several parameters, such as material properties including viscoelastic behavior of the cortical and trabecular bones, load amplitude, duration and direction on the instantaneous and long-term von Mises stress distribution of an implanted mandible were evaluated. In all loading conditions, the maximum von Mises stress occurred in cortical bone surrounding the neck of implant. Stress distribution was not noticeably affected by viscoelastic behavior during the first loading cycles, however, after 100 s periodic loading, the differences between stress magnitudes (especially in the cortical bone) became noticeable. In addition, sensitivity analysis showed that both cortical and trabecular bones were more sensitive to axial load than buccalingual and mesiodistal forces. The results of this study contribute to analysis of parameters involved in success of dental implantation.

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