scholarly journals Assessment of the Highest Stress Concentration Area Generated on the Mandibular Structure Using Meshless Finite Elements Analysis

2020 ◽  
Vol 7 (4) ◽  
pp. 142
Author(s):  
Andrea Fabra Rivera ◽  
Frederico de Castro Magalhães ◽  
Amalia Moreno ◽  
Juan Campos Rubio

Frequently, the oral cavity area can be affected by different diseases, so the patient needs to be submitted to surgery to remove a specific region of the mandibular. A complete or partial discontinuity of the mandibular bone can cause direct or indirect forces variations during the mastication. The dental prosthesis is an alternative to generate an aesthetic or functional solution for oral cavity lesions. However, they can be wrongly designed, or they can lose the adjustment during their useful life, deteriorating the patient’s condition. In this work, the influence of the fixation components position for a dental prosthesis will be studied based on the finite element method. By means, it is possible to determine the area of the highest stress concentration generated on the mandibular structure. The temporomandibular image obtained by computational tomography was used as a 3D graphic whole model because in the medical area the morphological factors are extremely important. Vertical loads of 50, 100, 150 and 200 N were applied in three different regions: in the whole buccal cavity, simultaneously in the left and right laterals and only in the right lateral, to determine the values of von Mises stress in the mandible. These results were compared between three finite element software packages (Ansys®, SolidWorks® and Inventor®) and a meshless software (SimSolid®). They showed similar behaviors in the highest mechanical stress concentration in the same regions. Regarding the stress values, the percentage error between each software package was less than 10%. The use of SimSolid® software (meshless) proved to be better at identifying the higher stress generated by the dental prosthesis in the facial skeleton, so its computational efficiency, due to its geometric complexity, was highlighted.

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Preeti Satheesh Kumar ◽  
Kumar K. S. Satheesh ◽  
Jins John ◽  
Geetha Patil ◽  
Ruchi Patel

Background and Objectives. A key factor for the long-term function of a dental implant is the manner in which stresses are transferred to the surrounding bone. The effect of adding a stiffener to the tissue side of the Hader bar helps to reduce the transmission of the stresses to the alveolar bone. But the ideal thickness of the stiffener to be attached to the bar is a subject of much debate. This study aims to analyze the force transfer and stress distribution of an implant-supported overdenture with a Hader bar attachment. The stiffener of the bar attachments was varied and the stress distribution to the bone around the implant was studied. Methods. A CT scan of edentulous mandible was used and three models with 1, 2, and 3 mm thick stiffeners were created and subjected to loads of emulating the masticatory forces. These different models were analyzed by the Finite Element Software (Ansys, Version 8.0) using von Mises stress analysis. Results. The results showed that the maximum stress concentration was seen in the neck of the implant for models A and B. In model C the maximum stress concentration was in the bar attachment making it the model with the best stress distribution, as far as implant failures are concerned. Conclusion. The implant with Hader bar attachment with a 3 mm stiffener is the best in terms of stress distribution, where the stress is concentrated at the bar and stiffener regions.


2014 ◽  
Vol 912-914 ◽  
pp. 589-592
Author(s):  
Jin Ling Wang

The design of cold punching mould CAD/CAM and the combination of CAE analysis can advance analysis of stamping process program, eventually get ideal stamping parameters, realize design automation, save resources and reduce dependence on experience, reduce the demand for skilled workers. This paper, by using nonlinear dynamic finite element software ANSYS/ls-dyna continuous function, simulation of sheet metal forming process and unloading plate deformation, forming process, at any time throughout the von mises stress nephogram should rebound and strain values and unloading plate material as a result, analysis help us better understand the changes of the internal material sheet metal stamping process.


2012 ◽  
Vol 214 ◽  
pp. 87-91
Author(s):  
Yuan Li ◽  
Chen Zhu

Three-ring reducer is a type of epicyclic gear drive with small tooth number difference and internal gear. It is different from other gear transmission, that the load shearing factor of multi tooth contact is much smaller. On the basis of analyses of geometry, tooth deformation and manufacturing errors, a mathematical model which describes the state of multi tooth contact and the load distribution characteristics of tooth was developed. The multi- tooth meshing effect of the three- ring gear reducer is studied used the finite element method and ANSYS finite element software. While three- ring gear reducer is running, the number of teeth contacted simultaneously, their load distribution characteristics and the von Mises stress change are gained.


2010 ◽  
Vol 452-453 ◽  
pp. 541-544 ◽  
Author(s):  
Yu Pu Song ◽  
Han Yong Liu

This work presents a study of a fatigue test and a finite element analysis on an arch bridge stainless steel suspender with threaded connections. A suspender which had a diameter of 70mm was tested under axial tensile loads range from 430kN to 700kN. The suspender was sudden failure from the thread root of the first loaded tooth in the pin after 1546609 cycles. Then, a two-dimensional axisymmetric modeling ignoring the helix angle of the thread was established with finite element software ANSYS to perform a stress analysis of the threaded connection. The stress concentration factors (SCFs) at the root of the teeth of pin were investigated under the applied external loading. The conclusive results had been drawn from the analysis including the location and the value of maximum SCF in the pin. Finally, the location and the value of the maximum von Mises stress were given. The results showed that the location of the fracture surface was consistent with the location of the maximum von Mises stress.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Chunping Lin ◽  
Hongcheng Hu ◽  
Junxin Zhu ◽  
Yuwei Wu ◽  
Qiguo Rong ◽  
...  

Abstract Background Stress concentration may cause bone resorption even lead to the failure of implantation. This study was designed to investigate whether a certain sagittal root position could cause stress concentration around maxillary anterior custom-made root-analogue implants via three-dimensional finite element analysis. Methods The von Mises stresses in the bone around implants in different groups were compared by finite element analysis. Six models were constructed and divided into two groups through Geomagic Studio 2012 software. The smooth group included models of unthreaded custom-made implants in Class I, II or III sagittal root positions. The threaded group included models of reverse buttress-threaded implants in the three positions. The von Mises stress distributions and the range of the stresses under vertical and oblique loads of 100 N were analyzed through ANSYS 16.0 software. Results Stress concentrations around the labial lamella area were more prominent in the Class I position than in the Class II and Class III positions under oblique loading. Under vertical loading, the most obvious stress concentration areas were the labial lamella and palatal apical areas in the Class I and Class III positions, respectively. Stress was relatively distributed in the labial and palatal lamellae in the Class II position. The maximum von Mises stresses in the bone around the custom-made root-analogue implants in this study were lower than around traditional implants reported in the literature. The maximum von Mises stresses in this study were all less than 25 MPa in cortical bone and less than 6 MPa in cancellous bone. Additionally, compared to the smooth group, the threaded group showed lower von Mises stress concentration in the bone around the implants. Conclusions The sagittal root position affected the von Mises stress distribution around custom-made root-analogue implants. There was no certain sagittal root position that could cause excessive stress concentration around the custom-made root-analogue implants. Among the three sagittal root positions, the Class II position would be the most appropriate site for custom-made root-analogue implants.


2012 ◽  
Vol 155-156 ◽  
pp. 531-534
Author(s):  
Yuan Li ◽  
Chen Zhu

Three-ring reducer is a type of epicyclic gear drive with small tooth number difference and internal gear. It is different from other gear transmission, that the load shearing factor of multi tooth contact is much smaller. On the basis of analyses of geometry, tooth deformation and manufacturing errors, a mathematical model which describes the state of multi tooth contact and the load distribution characteristics of tooth was developed. The multi- tooth meshing effect of the three- ring gear reducer is studied used the finite element method and ANSYS finite element software. While three- ring gear reducer is running, the number of teeth contacted simultaneously, their load distribution characteristics and the von Mises stress change are gained.


2010 ◽  
Vol 04 (04) ◽  
pp. 374-382 ◽  
Author(s):  
Oguz Eraslan ◽  
Ozgur Inan ◽  
Asli Secilmis

Objectives: The biomechanical behavior of the superstructure plays an important role in the functional longevity of dental implants. However, information about the influence of framework design on stresses transmitted to the implants and supporting tissues is limited. The purpose of this study was to evaluate the effects of framework designs on stress distribution at the supporting bone and supporting implants.Methods: In this study, the three-dimensional (3D) finite element stress analysis method was used. Three types of 3D mathematical models simulating three different framework designs for implant- supported 3-unit posterior fixed partial dentures were prepared with supporting structures. Convex (1), concave (2), and conventional (3) pontic framework designs were simulated. A 300-N static vertical occlusal load was applied on the node at the center of occlusal surface of the pontic to calculate the stress distributions. As a second condition, frameworks were directly loaded to evaluate the effect of the framework design clearly. The Solidworks/Cosmosworks structural analysis programs were used for finite element modeling/analysis.Results: The analysis of the von Mises stress values revealed that maximum stress concentrations were located at the loading areas for all models. The pontic side marginal edges of restorations and the necks of implants were other stress concentration regions. There was no clear difference among models when the restorations were loaded at occlusal surfaces. When the veneering porcelain was removed, and load was applied directly to the framework, there was a clear increase in stress concentration with a concave design on supporting implants and bone structure.Conclusions: The present study showed that the use of a concave design in the pontic frameworks of fixed partial dentures increases the von Mises stress levels on implant abutments and supporting bone structure. However, the veneering porcelain element reduces the effect of the framework and compensates for design weaknesses. (Eur J Dent 2010;4:374-382)


2019 ◽  
Vol 43 (4) ◽  
pp. 526-534
Author(s):  
Manbodh Kumar Das ◽  
Shibayan Sarkar ◽  
Bhanwar Singh Choudhary

Dragline teeth are used to dig overburden rocks and fill the bucket by its action in surface mining. Thus, these teeth are very important for a better performance of the dragline. In the present investigation, efforts were made to determine the failure zone within the teeth through modeling, using the finite element software ANSYS workbench. The maximum deformation and maximum von-Mises stress were 0.286 mm and 801.38 MPa, respectively. From fatigue analysis, the minimum tool life was 24 540 cycle and the minimum factor of safety was 0.1 at the tip of the tool. Beyond the cutting edge (tip), the factor of safety was greater than 1.13. Finite element analysis was extended by varying the working load on the edge of the tool (68–86 tonnes) as well as the cutting angle (30°–36°). It was found that if the working load was increased, both corresponding maximum deformation and maximum von-Mises stress were increased, while the factor of safety was decreased. In the scanning electron microscopy analysis, wear phenomena such as rock intermixed, fracture of WC-grain, oxidized WC-grain, plastic deformation, cavity formation, cracking, and crushing were visible at magnification of 1000×.


2011 ◽  
Vol 704-705 ◽  
pp. 1451-1457
Author(s):  
Lin Lin Luo ◽  
Da Sen Bi ◽  
Yan Bi ◽  
Liang Chu ◽  
Xu Ma ◽  
...  

Bending process is one of the important methods to form thick hull plate, whose accuracy is directly related to the quality of hull plate forming.In this paper, bending process of thick hull plate is simulated by using finite element software ANSYS, and some simulation results on bending deformation of thick hull plate such as the deformation of meshes in deformation zone, the distributions of the Von Mises stress and effective strain are obtained.


Author(s):  
Saeed Nokar ◽  
Hamid Jalali ◽  
Farideh Nozari ◽  
Mahnaz Arshad

Objectives: The success of implant treatment depends on many factors affecting the bone-implant, implant-abutment, and abutment-prosthesis interfaces. Stress distribution in bone plays a major role in success/failure of dental implants. This study aimed to assess the pattern of stress distribution in bone and abutment-implant interface under static and cyclic loadings using finite element analysis (FEA). Materials and Methods: In this study, ITI implants (4.1×12 mm) placed at the second premolar site with Synocta abutments and metal-ceramic crowns were simulated using SolidWorks 2007 and ABAQUS software. The bone-implant contact was assumed to be 100%. The abutments were tightened with 35 Ncm preload torque according to the manufacturer’s instructions. Static and cyclic loads were applied in axial (116 Ncm), lingual (18 Ncm), and mesiodistal (24 Ncm) directions. The maximum von Mises stress and strain values ​​were recorded. Results: The maximum stress concentration was at the abutment neck during both static and cyclic loadings. Also, maximum stress concentration was observed in the cortical bone. The loading stress was higher in cyclic than static loading. Conclusion: Within the limitations of this study, it can be concluded that the level of stress in single-unit implant restorations is within the tolerable range by bone.


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