scholarly journals Fatigue Analysis of NiTi Rotary Endodontic Files through Finite Element Simulation: Effect of Root Canal Geometry on Fatigue Life

2021 ◽  
Vol 10 (23) ◽  
pp. 5692
Author(s):  
Victor Roda-Casanova ◽  
Antonio Pérez-González ◽  
Álvaro Zubizarreta-Macho ◽  
Vicente Faus-Matoses
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Root Canal ◽  
Numerical Procedure ◽  
Element Model ◽  
Radius Of Curvature ◽  
Critical Plane ◽  
Element Analysis ◽  
Element Simulation ◽  
Critical Plane Approach

This article describes a numerical procedure for estimating the fatigue life of NiTi endodontic rotary files. An enhanced finite element model reproducing the interaction of the endodontic file rotating inside the root canal was developed, which includes important phenomena that allowed increasing the degree of realism of the simulation. A method based on the critical plane approach was proposed for extracting significant strain results from finite element analysis, which were used in combination with the Coffin–Manson relation to predict the fatigue life of the NiTi rotary files. The proposed procedure is illustrated with several numerical examples in which different combinations of endodontic rotary files and root canal geometries were investigated. By using these analyses, the effect of the radius of curvature and the angle of curvature of the root canal on the fatigue life of the rotary files was analysed. The results confirm the significant influence of the root canal geometry on the fatigue life of the NiTi rotary files and reveal the higher importance of the radius of curvature with respect to the angle of curvature of the root canal.

Multi-Axial Fatigue Life Model Evaluation and Life Prediction for Turbine Disk

2011 ◽  
Vol 130-134 ◽  
pp. 2330-2334
Author(s):  
Jun Hong Zhang ◽  
Feng Lv ◽  
Wen Peng Ma
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Low Cycle Fatigue ◽  
Turbine Disk ◽  
Strain History ◽  
Cycle Fatigue ◽  
Critical Plane ◽  
Element Analysis ◽  
Critical Plane Approach ◽  
Axial Fatigue

Multi-axial low cycle fatigue was the main failure mode of turbine disk. Critical plane approach was an idea method for the prediction of multi-axial fatigue life. A lot of models based on critical plane approach have been put forward, but there is not a universal prediction model. In order to find a model for turbine disk, linear heteroscedastic regression analysis of the standard low cycle fatigue data was carried out to obtained fatigue parameters. After verifying the accuracy of the finite element model, the stress and strain history of the danger point was obtained based on elastic-plastic finite element analysis. The critical plane and the damage of it was found by the method of coordinate transformation. The fatigue life of turbine disk was estimated by different models, and the results were quite different. SWT-Bannantine model was more suitable for the turbine disk.

Redrawing Operation a Star Shape from Cylindrical Shape Using Experimental and FE Analysis

2020 ◽  
Vol 38 (1A) ◽  
pp. 25-32
Author(s):  
Waleed Kh. Jawad ◽  
Ali T. Ikal
Keyword(s):  
Finite Element ◽  
Effective Strain ◽  
Element Model ◽  
Cylindrical Shape ◽  
Element Analysis ◽  
Punch Force ◽  
Maximum Value ◽  
Element Simulation ◽  
Blank Sheet ◽  
The Finite Element Model

The aim of this paper is to design and fabricate a star die and a cylindrical die to produce a star shape by redrawing the cylindrical shape and comparing it to the conventional method of producing a star cup drawn from the circular blank sheet using experimental (EXP) and finite element simulation (FES). The redrawing and drawing process was done to produce a star cup with the dimension of (41.5 × 34.69mm), and (30 mm). The finite element model is performed via mechanical APDL ANSYS18.0 to modulate the redrawing and drawing operation. The results of finite element analysis were compared with the experimental results and it is found that the maximum punch force (39.12KN) recorded with the production of a star shape drawn from the circular blank sheet when comparing the punch force (32.33 KN) recorded when redrawing the cylindrical shape into a star shape. This is due to the exposure of the cup produced drawn from the blank to the highest tensile stress. The highest value of the effective stress (709MPa) and effective strain (0.751) recorded with the star shape drawn from a circular blank sheet. The maximum value of lamination (8.707%) is recorded at the cup curling (the concave area) with the first method compared to the maximum value of lamination (5.822%) recorded at the cup curling (the concave area) with the second method because of this exposure to the highest concentration of stresses. The best distribution of thickness, strains, and stresses when producing a star shape by

Finite Element Analysis of the ESTELA M1 Airplane Firewall (Representative Specimen)

2011 ◽  
Author(s):  
V. Ramirez-Elias ◽  
E. Ledesma-Orozco ◽  
H. Hernandez-Moreno
Keyword(s):  
Finite Element ◽  
Federal Aviation Administration ◽  
Element Model ◽  
Maximum Load ◽  
Load Factor ◽  
Representative Specimen ◽  
Maximum Displacement ◽  
Element Analysis ◽  
Element Simulation ◽  
The Relationship

This paper shows the finite element simulation of a representative specimen from the firewall section in the AEROMARMI ESTELA M1 aircraft. This specimen is manufactured in glass and carbon / epoxy laminates. The specimen is subjected to a load which direction and magnitude are determined by a previous dynamic loads study [10], taking into account the maximum load factor allowed by the FAA (Federal Aviation Administration) for utilitarian aircrafts [11]. A representative specimen is manufactured with the same features of the firewall. Meanwhile a fix is built in order to introduce the load directions on the representative specimen. The relationship between load and displacement is plotted for this representative specimen, whence the maximum displacement at the specific load is obtained, afterwards it is compared with the finite element model, which is modified in its laminate thicknesses in order to decrease the deviation error; subsequently this features could be applied to perform the whole firewall analysis in a future model [10].

Stress and Fatigue Life Modeling of Cannon Breech Closures Including Effects of Material Strength and Residual Stress

2000 ◽  
Vol 123 (1) ◽  
pp. 150-154
Author(s):  
John H. Underwood ◽  
Michael J. Glennon
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Fatigue Life ◽  
Yield Strength ◽  
Residual Stresses ◽  
Solid Mechanics ◽  
Element Model ◽  
Pressure Vessels ◽  
Material Strength ◽  
Element Analysis

Laboratory fatigue life results are summarized from several test series of high-strength steel cannon breech closure assemblies pressurized by rapid application of hydraulic oil. The tests were performed to determine safe fatigue lives of high-pressure components at the breech end of the cannon and breech assembly. Careful reanalysis of the fatigue life tests provides data for stress and fatigue life models for breech components, over the following ranges of key parameters: 380–745 MPa cyclic internal pressure; 100–160 mm bore diameter cannon pressure vessels; 1040–1170 MPa yield strength A723 steel; no residual stress, shot peen residual stress, overload residual stress. Modeling of applied and residual stresses at the location of the fatigue failure site is performed by elastic-plastic finite element analysis using ABAQUS and by solid mechanics analysis. Shot peen and overload residual stresses are modeled by superposing typical or calculated residual stress distributions on the applied stresses. Overload residual stresses are obtained directly from the finite element model of the breech, with the breech overload applied to the model in the same way as with actual components. Modeling of the fatigue life of the components is based on the fatigue intensity factor concept of Underwood and Parker, a fracture mechanics description of life that accounts for residual stresses, material yield strength and initial defect size. The fatigue life model describes six test conditions in a stress versus life plot with an R2 correlation of 0.94, and shows significantly lower correlation when known variations in yield strength, stress concentration factor, or residual stress are not included in the model input, thus demonstrating the model sensitivity to these variables.

Outline of the Recent Consolidated Revision of EN13445-3, Clause 18 and Related Annexes: Detailed Assessment of Fatigue Life

2019 ◽  
Author(s):  
Jürgen Rudolph ◽  
Guy Baylac ◽  
Ralf Trieglaff ◽  
Rüdiger Gawlick ◽  
Michael Krämer ◽  
...  
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Assessment Method ◽  
Structural Stress ◽  
Critical Plane ◽  
Fatigue Assessment ◽  
European Working ◽  
Critical Plane Approach ◽  
Detailed Assessment

Abstract The European Pressure Vessel Standard EN 13445 (harmonized Standard acc. to PED 2014/68/EU) provides in its Part 3 (Design) a simplified method for fatigue assessment (Clause 17) and a detailed method of fatigue assessment (Clause 18). While the new revision of Clause 17 has already been adopted, Clause 18 “Detailed Assessment of Fatigue Life” is now available as a consolidated revision in inquiry phase. This major and comprehensive revision has been developed within the framework of the European working group CEN/TC 54/WG 53 – Design methods and constitutes a crucial step towards a modern and user-friendly engineering fatigue assessment method. The overall structure and amendments of Clause 18 are to be presented. All these amendments aim at a significant increase in user friendliness and clear guidelines for application. The following items are to be mentioned in that context: • Fatigue assessment of welded components based on structural stress and structural hot-spot stress approaches, • Detailed guidelines for determining relevant stresses and stress ranges, • Cycle counting proposals in the context of the fatigue assessment method including a critical plane approach. The fatigue assessment of welded components is separated from the fatigue assessment of un-welded parts as it has already been done in previous versions with respective methodological differences. Stress analyses for clause 18 are usually based on detailed finite element analyses (FEA). As an essential amendment for the user, the determination of structural stress ranges for the fatigue assessment of welds is further detailed in a new appropriate annex. Different applicable methods for the determination of structural stresses are explained in connection with the requirements of the finite element models and analyses. The cycle counting issue is comprehensively treated in the context of different design and operation situations (design transients, operational stress-time-histories). The description is detailed towards a critical plane approach. Detailed proposals for implementation in an algorithmic programming framework are given making the described methods ready to use.

Random Vibration Structure Fatigue Analysis Based on Finite Element Simulation

2014 ◽  
Vol 875-877 ◽  
pp. 2078-2086
Author(s):  
Long Tao Liu ◽  
Chuan Ri Li ◽  
Shuang Long Rong ◽  
You Gang Jin
Keyword(s):  
Finite Element ◽  
Random Vibration ◽  
Element Model ◽  
Product Structure ◽  
Structure Design ◽  
Frequency Domain Method ◽  
Element Analysis ◽  
Power Spectral ◽  
Element Simulation ◽  
The Finite Element Analysis

In order to analyze the fatigue of the airborne product structure, the modal analysis and random vibration analysis are conducted for the product by using the finite element analysis software ANSYS. The modal analyzing results are compared with the modal test results and the finite element model is corrected. The stress response power spectral density is obtained from random vibration analyzing. A frequency domain method for calculating the fatigue damage of the structure is presented. The simulation results are in agreement with the reliability enhancement testing results. An optimization scheme for the product structure design is given.

Finite Element Simulation Technique for Evaluation of Opening Stresses Under High Plasticity

2020 ◽  
Author(s):  
Ans Al Rashid ◽  
Ramsha Imran ◽  
Muhammad Yasir Khalid
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Life ◽  
Mechanical Behavior ◽  
Finite Element Simulation ◽  
Simulation Technique ◽  
High Plasticity ◽  
Element Analysis ◽  
Element Simulation ◽  
Stress Levels

Abstract The mechanical behavior of materials plays a vital role in the structural performance of designed structures. Therefore, significant resources are devoted globally towards experimental characterization of material behavior, especially for the experiments requiring particular protocols. Contrary, finite element analysis tools have made a substantial contribution to the design of structural elements, which could conserve a significant amount of resources and material wastage. Evaluation of fatigue life of materials is necessary to predict the life expectancy of the structures precisely, and opening stress levels under fatigue loading contributes towards this evaluation. Railways serve as freight and passenger carrier transportation modes. The railway axles contribute as the primary load-carrying element; therefore, the design of railway axles and the study of their mechanical behavior under repeated loading is vital. In this study, the authors present a finite element simulation technique to evaluate the opening stress levels for two structural steels subjected to low cycle fatigue. The finite element analysis (FEA) model was designed and validated following the simulation of fatigue crack propagation under high plasticity conditions. Numerical simulation results were compared with the experimental results obtained earlier through the digital image correlation (DIC) technique. To conclude, FEA could be a useful tool to predict crack closure phenomena and, ultimately, the fatigue life of components. However, researchers need to establish more sophisticated numerical tools for more precise results in case of high plasticity conditions near the crack tip.

Finite Element Simulation of Grinding Stress for a Fiber Optic Connector (Ceramic Ferrule)

2005 ◽  
Vol 297-300 ◽  
pp. 2327-2332 ◽  
Author(s):  
Chang Min Suh ◽  
Ki Sang Jung
Keyword(s):  
Finite Element ◽  
Fiber Optic ◽  
Geometric Model ◽  
Element Model ◽  
Grinding Force ◽  
Element Analysis ◽  
Element Simulation ◽  
Dimensional Finite Element ◽  
Input Variables ◽  
High Level

Ceramic ferrule that is a major part of the optic connectors requires a high level of precision in a grinding chamfer. After the grinding chamfer, there is a problem in that the subsurface damages cannot be removed. The objective of this study was to analyze the grinding force and the associated stress generated in a ceramic ferrule during cylindrically grinding chamfer using Finite Element Analysis (FEA). A two-dimensional finite element model was constructed with the grinding parameters and the mechanical properties of the ferrule as input variables. The size of the geometric model was the same with the ceramic ferrule. The experimental results achieved by the SEM photograph were compared with those from the FEM. The FEM results were in correlation with those of the experiments.

scholarly journals Modeling and Simulation of Architectured Iron-Based SMA Materials

2017 ◽  
Author(s):  
Wael Zaki ◽  
Cheikh Cissé ◽  
Tarak Ben Zineb
Keyword(s):  
Finite Element ◽  
Bulk Material ◽  
Computation Time ◽  
Element Model ◽  
Unit Cell ◽  
Element Analysis ◽  
Geometric Patterns ◽  
Element Simulation ◽  
Iron Based ◽  
As Stress

The paper presents results of finite element analysis of architectured iron-based shape memory alloy (SMA) samples consisting of bulk SMA and void combined to different proportions and according to different geometric patterns. The finite element simulation uses a constitutive model for iron-based SMAs that was recently developed by the authors in order to account for the behavior of the bulk material. The simulation of the architectured SMA is then carried out using a unit cell method to simplify calculations and reduce computation time. For each unit cell, periodic boundary conditions are assumed and enforced. The validity of this assumption is demonstrated by comparing the average behavior of one unit cell to that of a considerably larger sample comprising multiple such cells. The averaging procedure used is implemented numerically, by calculating volume averages of mechanical fields such as stress and strain over each finite element model considered as a combination of mesh elements.

Finite Element Analysis and Optimal Design of Commercial Vehicle Drive Axle Housing

2013 ◽  
Vol 816-817 ◽  
pp. 782-785 ◽  
Author(s):  
Bing Bing Zhou ◽  
Hui Lin Li ◽  
Qian Liu
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Commercial Vehicle ◽  
Element Model ◽  
Optimization Method ◽  
Bench Test ◽  
Dynamics Analysis ◽  
Element Analysis ◽  
Drive Axle ◽  
Drive Axle Housing

In order to solve the heavy mass problem of the commercial vehicle drive axle housing, the structure of axle housing is optimized with finite element method. At first, the parametric finite element model of axle housing is built by using ANSYS software, and the dynamic response characteristics of axle housing are obtained with transient dynamics analysis. The dynamic analysis results show that strength and stiffness of axle housing can satisfy design criteria very well. Then the fatigue life of axle housing are predicted based on the dynamics analysis, and results show that the fatigue dangerous regions occur on the spring seats. Finally, the structure optimization of axle housing is done aimed at lightweight with goal drive optimization method, and the fatigue life of optimized axle housing are verified with FEA and bench test. The results of verification by both FEA and test show that the optimized axle housing has apparent lightweight effects with its fatigue life meeting design requirements.

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