Fastener Pattern Optimization of an Eccentrically Loaded Multi-Fastener Connection

2010 ◽  
Author(s):  
Matthew Watkins ◽  
Mark Jakiela
Keyword(s):  
Stress Concentration ◽  
Maximum Stress ◽  
Fatigue Cracks ◽  
Frictional Resistance ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Fastener Hole ◽  
Type Contact ◽  
Instantaneous Center ◽  
Von Mises

This paper presents the use of a genetic algorithm in conjunction with geometric nonlinear finite element analysis to optimize the fastener pattern and lug location in an eccentrically loaded multi-fastener connection. No frictional resistance to shear was included in the model, as the connection transmitted shear loads into four dowel fasteners through bearing-type contact without fastener preload. With the goal of reducing the maximum von Mises stress in the connection to improve fatigue life, the location of the lug hole and four fastener holes were optimized to achieve 55% less maximum stress than a similar optimization using the traditional instantaneous center of rotation method. Since the maximum stress concentration was located at the edge of a fastener hole where fatigue cracks could be a concern, reduction of this quantity lowers the probability of crack growth for both bearing-type and slip-resistant connections. It was also found that the location of the maximum von Mises stress concentration jumped from the fastener region to the lug as the applied force angle was decreased below 45 degrees, thus the fastener pattern could not be optimized for lower angles.

scholarly journals Finite Element Analysis of Stress in Bone and Abutment-Implant Interface under Static and Cyclic Loadings

2020 ◽  
Author(s):  
Saeed Nokar ◽  
Hamid Jalali ◽  
Farideh Nozari ◽  
Mahnaz Arshad
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Stress Distribution ◽  
Maximum Stress ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Bone Implant ◽  
Factors Affecting ◽  
Von Mises

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.

scholarly journals Force Transfer and Stress Distribution in an Implant-Supported Overdenture Retained with a Hader Bar Attachment: A Finite Element Analysis

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Preeti Satheesh Kumar ◽  
Kumar K. S. Satheesh ◽  
Jins John ◽  
Geetha Patil ◽  
Ruchi Patel
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Stress Distribution ◽  
Maximum Stress ◽  
Alveolar Bone ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Finite Element Software ◽  
Force Transfer ◽  
Edentulous Mandible

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.

scholarly journals Evaluation of Stress Distribution and Force in External Hexagonal Implant: A 3-D Finite Element Analysis

2021 ◽  
Vol 18 (19) ◽  
pp. 10266
Author(s):  
Vinod Bandela ◽  
Ram Basany ◽  
Anil Kumar Nagarajappa ◽  
Sakeenabi Basha ◽  
Saraswathi Kanaparthi ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Maximum Stress ◽  
Axial Direction ◽  
Von Mises Stress ◽  
P Value ◽  
Implant Surface ◽  
Element Analysis ◽  
Von Mises

Purpose: To analyze the stress distribution and the direction of force in external hexagonal implant with crown in three different angulations. Materials and Methods: A total of 60 samples of geometric models were used to analyze von Mises stress and direction of force with 0-, 5-, and 10-degree lingual tilt. Von Mises stress and force distribution were evaluated at nodes of hard bone, and finite element analysis was performed using ANSYS 12.1 software. For calculating stress distribution and force, we categorized and labeled the groups as Implant A1, Implant A2, and Implant A3, and Implant B1, Implant B2, and Implant B3 with 0-, 5-, and 10-degree lingual inclinations, respectively. Inter- and intra-group comparisons were performed using ANOVA test. A p-value of ≤0.05 was considered statistically significant. Results: In all the three models, overall maximum stress was found in implant model A3 on the implant surface (86.61), and minimum was found on model A1 in hard bone (26.21). In all the three models, the direction of force along three planes was maximum in DX (0.01025) and minimum along DZ (0.002) direction with model B1. Conclusion: Maximum von Mises stress and the direction of force in axial direction was found at the maximum with the implant of 10 degrees angulation. Thus, it was evident that tilting of an implant influences the stress concentration and force in external hex implants.

Finite Element Analysis on Structural Stress of 16×16 InSb IRFPA with Viscoelastic Underfill

2011 ◽  
Vol 314-316 ◽  
pp. 530-534 ◽  
Author(s):  
Li Wen Zhang ◽  
Jin Chan Wang ◽  
Qian Yu ◽  
Qing Duan Meng
Keyword(s):  
Finite Element ◽  
Maximum Stress ◽  
Viscoelastic Model ◽  
Finite Element Method Simulation ◽  
Von Mises Stress ◽  
Structural Stress ◽  
Element Analysis ◽  
Indium Bump ◽  
Final Yield ◽  
Von Mises

The thermal stress and strain, from the thermal mismatch of neighboring materials, are the major causes of fracture in InSb IRFPA. Basing on viscoelastic model describing underfill, the structural stress of 16×16 InSb IRFPA under thermal shock is studied with finite element method. Simulation results show that as the diameters of indium bump increase from 20μm to 36μm in step of 2μm, the maximum stress existing in InSb chip first increases slightly, and fluctuates near 28µm, then decreases gradually. Furthermore, the varied tendency seems to have nothing to do with indium bump standoff height, and with thicker indium bump height, the maximal Von Mises stress in InSb chip is smaller. All these mean that the thicker underfill is in favor of reducing the stress in InSb chip and improving the final yield.

scholarly journals Elastic stress concentration at radial crossholes in pressurized thick cylinders

2007 ◽  
Vol 42 (6) ◽  
pp. 461-468 ◽  
Author(s):  
T Comlekci ◽  
D Mackenzie ◽  
R Hamilton ◽  
J Wood
Keyword(s):  
Stress Concentration ◽  
Maximum Stress ◽  
Equivalent Stress ◽  
Three Dimensional ◽  
Maximum Principal Stress ◽  
Radius Ratio ◽  
Graphical Form ◽  
Element Analysis ◽  
Parametric Finite Element Analysis ◽  
Von Mises

Results of a parametric finite element analysis investigation of stress concentration at radial crossholes in pressurized cylinders are presented in numerical and graphical form. The analysis shows that the location of maximum stress does not generally occur at the junction between the bores, as is commonly supposed, but at some small distance up the crosshole from the junction. Maximum stress concentration factors (SCFs) are defined on the basis of the maximum principal stress, von Mises equivalent stress, and stress intensity. Three-dimensional plots of the SCF against the cylinder radius ratio b/a and the crosshole-to-main-bore-radius ratio c/a are presented. The SCFs were found to vary across the range of geometries considered with local minima identified within the parameter range in most cases. The results therefore allow designers to select optimum b/a and c/a ratios to minimize stress concentration in real problems.

scholarly journals Influence of Sagittal Root Positions on the Stress Distribution Around Custom-made Root-analogue Implants: A Three-dimensional Finite Element Analysis

2021 ◽  
Author(s):  
Chunping Lin ◽  
Hongcheng Hu ◽  
Junxin Zhu ◽  
Yuwei Wu ◽  
Qiguo Rong ◽  
...  
Keyword(s):  
Stress Concentration ◽  
Three Dimensional ◽  
Class Ii ◽  
Class I ◽  
Von Mises Stress ◽  
Class Iii ◽  
Element Analysis ◽  
Custom Made ◽  
Root Position ◽  
Von Mises

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: Six models were constructed and divided into two groups. 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. Stress distributions under vertical and oblique loads of 100 N were analyzed.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 stress in the bone around the custom-made root-analogue implants in this study was lower than around traditional implants reported in the literature. Additionally, compared to the smooth group, the threaded group showed lower von Mises stress 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.

scholarly journals Influence of sagittal root positions on the stress distribution around custom-made root-analogue implants: a three-dimensional finite element analysis

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Chunping Lin ◽  
Hongcheng Hu ◽  
Junxin Zhu ◽  
Yuwei Wu ◽  
Qiguo Rong ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Class I ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Custom Made ◽  
Root Position ◽  
Von Mises ◽  
Von Mises Stresses

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.

Comparison of Materials for Universal Tractor Connecting Rod Using Ansys Software

2014 ◽  
Vol 592-594 ◽  
pp. 1015-1019
Author(s):  
Ritesh Kumar Patel ◽  
Surjit Angra ◽  
Vinod Kumar Mittal
Keyword(s):  
Maximum Stress ◽  
Combustion Engine ◽  
Material Selection ◽  
Static Strength ◽  
Von Mises Stress ◽  
Connecting Rod ◽  
Element Analysis ◽  
Von Mises ◽  
And Function ◽  
Selection Of

Connecting rod is one of the most important components of an internal combustion engine and transfers motion from the piston to the crankshaft and function as a lever arm. Existing connecting rod is manufactured by using C-70 alloy steel. In the current study, connecting rod is replaced by E-glass/Epoxy composite material for universal tractor. The static strength of connecting rod is analyzed in detail and the maximum stress is found. Some improvement methods are also provided for the material selection of connecting rod. Connecting rod is modeled in CATIA V5 software and it is imported in ANSYS 14 workbench for analysis. The main objective of this study is to perform the static analysis of universal tractor connecting rod to find out its static strength using ANSYS 14 workbench. Finite element analysis is done by considering composite materials. The best combination of parameters like Von mises stress, deformation and weight reduction for connecting rod is carried out.

scholarly journals KERUSAKAN DAN PERANCANGAN ULANG ALTERNATIF GIRDER PADA LINTASAN TRIPPER SESUAI SNI 03-1729-2002

2016 ◽  
Vol 17 (3) ◽  
pp. 167
Author(s):  
Djoko W Karmiadji ◽  
Rhandi Mulia ◽  
Eddy Djatmiko
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Maximum Stress ◽  
Von Mises Stress ◽  
Structural Failure ◽  
Element Analysis ◽  
Mechanical Calculation ◽  
Design Alternatives ◽  
Von Mises ◽  
Calculation Analysis

<p>Abstrak<br />Kegagalan fungsi girder pada lintasan tripper yang sering terjadi disebabkan oleh keretakan pada penopang silang dan tegak, terjadinya defleksi berlebih pada batang utama, dan perubahan posisi pada kedua kolom. Kerusakan strukur diakibatkan oleh ketidaksesuaian pembebanan yang diterima, sehingga memperlemah komponennya dan dapat berakibat runtuhnya struktur girder. Studi dilakukan dengan mengkaji desain yang sudah ada melalui pendefenisian pembebanan, selanjutnya melakukan perhitungan mekanika pada tiga model pembebanan yang berbeda dan pengecekan kelayakan desain dengan metode LRFD berdasarkan SNI 03-1729-2002 dengan validasi menggunakan analisis elemen hingga. Hasil menunjukkan terjadinya ketidaksesuaian pembebanan yang berakibat kerusakan girder, sehingga diperlukan desain alternatif melalui pemilihan profil, perhitungan kelayakan profil dan analisis ulang untuk memastikan kehandalan rancangan. Dari hasil analisis perhitungan dapat disimpulkan bahwa desain alternatif mempunyai kehandalan yang memadai yaitu defleksinya 0,35 mm dibanding desain lama 15,96 mm berdasarkan perhitungan mekanik, sedangkan hasil analisis elemen hingga, defleksi desain baru 1,08 mm dan desain lama 10,37 mm. Tegangan maksimum desain baru adalah aman terhadap material yang digunakan, yaitu SS400 dengan kekuatan sebesar 245 MPa, dimana hasil perhitungan mekanika diperoleh tegangan maksimum desain baru 52,00 MPa, sedangkan tegangan maksimum hasil analisis elemen hingga adalah 56,31 MPa dan tegangan Von Mises 143,39 MPa.<br />Kata kunci : girder, tripper, LFRD, elemen hingga, Standar Nasional Indonesia (SNI).</p><p><br />Abstract<br />Malfunction of girder on track tripper that often occurred is caused by cracks in the cross and upright supports, occurrence of excessive deflection on main bar, and a change in position of the both columns. Structural failure is caused by loading discrepancies received, so it is weaken its components and resulted in the collapse of the girder structure. The study was conducted by reviewing existing design through loading analysis, then performing the mechanical calculation on three different loading models and checking the feasibility of the design with LRFD method based on SNI 03-1729-2002 with validation using finite element analysis. Results showed the loading discrepancies resulting in damaged girder, so it is necessary to make design alternatives through the selection of profiles, re-calculation and feasibility analysis of the beam to ensure the reliability of the design. From the calculation analysis, it can be concluded that the alternative design has adequate reliability. Based on mechanical calculations the deflection is 0.35 mm compared to 15.96 mm of the old design, while the result of finite element analysis determine 1.08 mm deflection of the new design and 10.37 mm in old design. The maximum stress of the new design is safe for the material used, ie SS400 with a strength of 245 MPa, wherein mechanical calculation resulted in obtained maximum stress of the new design is 52.00 MPa, while the maximum stress through finite element analysis result is 56.31 MPa and Von Mises stress is 143.39 Mpa.<br />Keywords: girder, tripper, LFRD, finite element, National Indonesian Standard (SNI).</p>

Finite element analysis of endodontically treated tooth restored with different posts under thermal and mechanical loading

2011 ◽  
Vol 1 (3) ◽  
pp. 75 ◽  
Author(s):  
Ozkan ADIGÜZEL ◽  
Senem YİĞİT ÖZER ◽  
Emrullah BAHŞİ ◽  
İzzet YAVUZ
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Mechanical Loading ◽  
Maximum Stress ◽  
Von Mises Stress ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Endodontically Treated Tooth ◽  
Von Mises ◽  
Titanium Post

Aim: This study compared the stress distributions of endodontically treated tooth restored with carbon and titanium post under thermal and mechanical loading conditions. Methodology: A 3-dimensional finite element model was created to represent in a labiolingual cross-sectional view of an endodontically treated maxillary central incisor tooth with its supporting structures. It was modified according to two post systems with different physical properties consisting titanium, and carbon fiber. Stress distribution and stress values were then calculated by considering the three dimensional von Mises stress criteria. Results: A 100-N static vertical occlusal load was applied on the node at the center of occlusal surface of the tooth. The von Mises stress values for carbon post model was on the coronal third and the cervical area of the root in the range of 436,16 and 3,59 MPa,  for titanium post model was 590,55 and 3,05 MPa. Thermal stress values for carbon post model showed that maximum stress concentrations were noted on the coronal third and the top of the post area of the root in the range of 509,94 and 6,38 MPa. Titanium post model showed that maximum stress concentrations were noted on the coronal third and top of the post area of the root in the range of 1165,06 and 3,06 MPa. Conclusion: This study shows that the titanium post yields larger stresses than the carbon post under thermal conditions.  How to cite this article: Adıgüzel Ö, Yiğit Özer S, Bahşi E, Yavuz İ. Finite element analysis of endodontically treated tooth restored with different posts under thermal and mechanical loading. Int Dent Res 2011;3:75-80. Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Sign in / Sign up

Export Citation Format

Share Document