scholarly journals Three-Dimensional Finite Element Analysis of Anterior Single Implant-Supported Prostheses with Different Bone Anchorages

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Fellippo Ramos Verri ◽  
Joel Ferreira Santiago Júnior ◽  
Daniel Augusto de Faria Almeida ◽  
Ana Caroline Gonçales Verri ◽  
Victor Eduardo de Souza Batista ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Anterior Region ◽  
Bone Block ◽  
Apical Region ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Biomechanical Behavior ◽  
Nasal Floor

The aim of this study was to evaluate the stress distribution of monocortical and bicortical implant placement of external hexagon connection in the anterior region of the maxilla by 3D finite element analysis (FEA). 3D models were simulated to represent a bone block of anterior region of the maxilla containing an implant (4.0 × 10.0 mm) and an implant-supported cemented metalloceramic crown of the central incisor. Different techniques were tested (monocortical, bicortical, and bicortical associated with nasal floor elevation). FEA was performed in FEMAP/NeiNastran software using loads of 178 N at 0°, 30°, and 60° in relation to implant long axis. The von Mises, maximum principal stress, and displacement maps were plotted for evaluation. Similar stress patterns were observed for all models. Oblique loads increased the stress concentration on fixation screws and in the cervical area of the implants and bone around them. Bicortical technique showed less movement tendency in the implant and its components. Cortical bone of apical region showed increase of stress concentration for bicortical techniques. Within the limitations of this study, oblique loading increased the stress concentrations for all techniques. Moreover, bicortical techniques showed the best biomechanical behavior compared with monocortical technique in the anterior maxillary area.

Stress analysis of axisymmetric butt joints loaded in torsion and tension

1978 ◽  
Vol 13 (1) ◽  
pp. 1-10 ◽  
Author(s):  
R D Adams ◽  
J Coppendale ◽  
N A Peppiatt
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Stress Analysis ◽  
Stress Distributions ◽  
Stress Concentrations ◽  
Adhesive Properties ◽  
Butt Joints ◽  
Element Analysis ◽  
Tensile Stresses

Axisymmetric butt joints are widely used as specimens for testing the response of adhesives to shear and tensile stresses. When analysing the results from these tests, the stress distributions must be accurately known. A finite-element analysis has been used to examine the effect of non-rigid adherends and a spew fillet in solid and annular butt joints for a range of geometries and adhesive properties. It has been shown that stress concentrations occur in butt joints loaded in tension; in the latter case, the stress concentration is directly due to the presence of the spew fillet.

Proposition of Helical Thread Modeling With Accurate Geometry and Finite Element Analysis

2006 ◽  
Author(s):  
Toshimichi Fukuoka ◽  
Masataka Nomura ◽  
Yuuya Morimoto
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Contact Pressure ◽  
Three Dimensional ◽  
Bolted Joints ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Pressure Distributions ◽  
Thread Root

Distinctive mechanical behavior of bolted joints is caused by the helical shape of thread geometry. Recently, a number of papers have been published to elucidate the strength or loosening phenomena of bolted joints using three-dimensional finite element analysis. In most cases, mesh generations of the bolted joints are implemented with the help of sophisticated software. The mesh patterns so obtained are, therefore, not necessarily adequate for analyzing the stress concentration and contact pressure distributions, which are the primary concerns when designing bolted joints. In this paper, an effective mesh generation scheme is proposed, which can provide a helical thread model with accurate geometry in order to analyze such important characteristics as stress concentrations and contact pressure distributions along the thread helix. Using the FE models with accurate thread geometry, it is shown how the thread root stress and contact pressure vary along the helix and nut loaded surface and how the chamfering of the top threads of the nut mitigate the stress concentration concerned.

On the Generation of Tuned Test Problems for Stress Concentrations

2021 ◽  
Author(s):  
Glenn Sinclair ◽  
Ajay A Kardak
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Precise Determination ◽  
Test Problems ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Concentration Factors ◽  
Stress Concentration Factors

Abstract When stress concentration factors are not available in handbooks, finite element analysis has become the predominant method for determining their values. For such determinations, there is a need to know if they have sufficient accuracy. Tuned Test Problems can provide a way of assessing the accuracy of stress concentration factors found with finite elements. Here we offer a means of constructing such test problems for stress concentrations within boundaries that have local constant radii of curvature. These problems are tuned to their originating applications by sharing the same global geometries and having slightly higher peak stresses. They also have exact solutions, thereby enabling a precise determination of the errors incurred in their finite element analysis.

scholarly journals Different bone anchorages for Morse taper implants with different lengths in maxilla anterior: An in silico analysis

2021 ◽  
Vol 10 (9) ◽  
pp. e57010917729
Author(s):  
Hiskell Fernandes Fernandes e Oliveira ◽  
Cleidiel Araujo Lemos ◽  
Ronaldo Silva Cruz ◽  
Victor Eduardo de Souza Batista ◽  
Rodrigo Capalbo da Silva ◽  
...  
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Bone Tissue ◽  
3D Models ◽  
Von Mises Stress ◽  
Bone Block ◽  
Apical Region ◽  
Biomechanical Behavior ◽  
Single Crown ◽  
Nasal Floor

This study aimed to evaluate the stress distribution in bone tissue, in Morse tapper implants and components supporting a single crown in the maxillary anterior area, under different bone anchorages (conventional, bicortical and bicortical with nasal floor elevation) and implant lengths (8.5 mm, 10 mm and 11.5 mm) using 3D finite element analyses. Three 3D models including element #11 were simulated using software InVesalius, Rhinoceros 3D and SolidWorks. Bone block models were reconstructed from computed tomography and simulated the placement of one implant of 4 mm of diameter and lengths above mentioned, supporting cemented zirconia crown. The 3D models were processed by the finite element FEMAP and NeiNastran software, using a load of 178N were applied at 0º, 30º and 60º, considering the implant long axis. Results were visualized as the von Mises stress, maximum principal stress and microstrain maps. Bicortical bone anchorages showed lower stress and microstrain bone tissue when compared to conventional bone anchorage. However, no differences were observed between bicortical and nasal floor elevation. Regarding implants and components, the stress distribution was similar between models with little stress relief in the apical region of the implants for implants with conventional anchorage. The conclusion drawn from this study is that non-axial loading showed worse biomechanical behavior for bone tissue and implants/components. The bicortical techniques (bicortical and nasal floor elevation) should be preferred during the implant placement to reduce the stress and microstrain in the bone tissue.

scholarly journals Influence of Preparation Design, Restorative Material and Load Direction on The Stress Distribution of Ceramic Veneer in Upper Central Incisor

2021 ◽  
Vol 24 (3) ◽  
Author(s):  
Laura Célia Fernandes Meirelles ◽  
Fernanda Zapater Pierre ◽  
João Paulo Mendes Tribst ◽  
Clovis Pagani ◽  
Eduardo Bresciani ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Stress Distribution ◽  
Lithium Disilicate ◽  
Occlusal Plane ◽  
Central Incisor ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Preparation Design

Objective: Evaluate the effect of four preparation designs, two ceramic materials, and two occlusion contact types on the stress distribution of ceramic veneer in upper central incisor. Material and methods:  3D-models were performed in the modeling software containing enamel, dentin, pulp, periodontal ligament and a base of polyurethane resin. The designs were modeled and exported to the computer aided engineering software to perform the static structural analysis. For the mesh, a total of 155429 tetrahedron elements and 271683 nodes were used, after a 10% convergence test. Two materials, lithium disilicate and feldspathic ceramics, were simulated. A static load of 100 N on 45º was applied on the incisal and middle thirds of the palatal tooth region, guided by the occlusal plane. The base was constrained in all directions. The Maximum Principal Stress was the failure criteria chosen for the analysis. Results: The Finite Element Analysis showed that the most conservative designs presented less stress concentration on the ceramic veneer. However, the highest tensile stress concentrations were observed on lithium disilicate veneer with extend design, on the middle third. The type of occlusal contact presented different stress patterns among the preparation designs; the incisal contact showed higher stress concentration compared to middle third contact regardless the ceramic material. Conclusions: To perform a ceramic veneer in upper central incisor, the feldspathic ceramic presented promising results and should be recommended when the extended design was done. Regarding contact types, the incisal contact is more prone to failure regardless the ceramic and preparation design.   Keywords Ceramics; Dental veneers; Finite element analysis.

Stress Analysis and Structure Optimization for the Opening Flat Cover of Pressure Vessels

2012 ◽  
Vol 538-541 ◽  
pp. 3253-3258 ◽  
Author(s):  
Jun Jian Xiao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Stress Analysis ◽  
Structure Optimization ◽  
Pressure Vessels ◽  
Secondary Stress ◽  
Element Analysis ◽  
Primary Stress ◽  
Flat Cover

According to the results of finite element analysis (FEA), when the diameter of opening of the flat cover is no more than 0.5D (d≤0.5D), there is obvious stress concentration at the edge of opening, but only existed within the region of 2d. Increasing the thickness of flat covers could not relieve the stress concentration at the edge of opening. It is recommended that reinforcing element being installed within the region of 2d should be used. When the diameter of openings is larger than 0.5D (d>0.5D), conical or round angle transitions could be employed at connecting location, with which the edge stress decreased remarkably. However, the primary stress plus the secondary stress would be valued by 3[σ].

An Estimation Formula of the Stress Concentration Factor of the Butt-Welded Joint

2007 ◽  
Vol 353-358 ◽  
pp. 1995-1998
Author(s):  
Byeong Choon Goo
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Gas Metal Arc Welding ◽  
Element Analysis ◽  
Butt Weld ◽  
Estimation Formula ◽  
Metal Arc Welding ◽  
Concentration Factors ◽  
Stress Concentration Factors

The purpose of this paper is to develop an estimation formula of stress concentration factors of butt-welded components under tensile loading. To investigate the influence of weld bead profiles on stress concentration factors of double V groove butt-welded joints, butt-welded specimens were made by CO2 gas metal arc welding. And the three main parameters, the toe radius, flank angle and bead height were measured by a profile measuring equipment. By using the measured data, the influence of three parameters on the stress concentration factors was investigated by a finite element analysis. It is shown that the three parameters have similar effects on the stress concentration factors. According to the simulation results, a formula to estimate the stress concentration factors of butt-weld welded structures was proposed and the estimated concentration factors from the formula were compared with the results obtained by the finite element analysis. The two results are in a good agreement.

Practical Procedures for Technical and Economic Investigation of Ship Structural Details

1981 ◽  
Vol 18 (01) ◽  
pp. 51-68
Author(s):  
Donald Liu ◽  
Abram Bakker
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Analysis Techniques ◽  
Structural Problems ◽  
Analysis Technique ◽  
The Finite Element Analysis ◽  
Structural Details

Local structural problems in ships are generally the result of stress concentrations in structural details. The intent of this paper is to show that costly repairs and lay-up time of a vessel can often be prevented, if these problem areas are recognized and investigated in the design stages. Such investigations can be performed for minimal labor and computer costs by using finite-element analysis techniques. Practical procedures for analyzing structural details are presented, including discussions of the results and the analysis costs expended. It is shown that the application of the finite-element analysis technique can be economically employed in the investigation of structural details.

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