scholarly journals Simulation of Fatigue Failure of Rail Joint Bolts by FEA

2011 ◽  
Vol 2-3 ◽  
pp. 1035-1040 ◽  
Author(s):  
Xiao Peng Li ◽  
Hui Fan Nie ◽  
Wei Jie Yuan ◽  
Bang Chun Wen
Keyword(s):  
Finite Element ◽  
Fatigue Strength ◽  
Stress Concentration ◽  
Influencing Factors ◽  
Fatigue Failure ◽  
Impact Force ◽  
Working Life ◽  
Analysis Method ◽  
Bolt Failure ◽  
Temperature Force

It is well known that the fatigue failure of bolts can affect the performance of rail joint and the safety of train running. In this work, the influence of the bolt torque and radius of rounded root of rail bolt on the fatigue strength of the rail bolt are studied by Finite Element Contact Analysis method. And the influence effects of the wheel impact and temperature force of the rail caused by temperature changed on bolt failure are studied. The results indicate that properly torque and increasing the radius of rounded root rail bolt can reduce the stress concentration at the root of rail bolt and this will improves the fatigue strength and the working life of the rail bolt and rail joint. The repeated temperature force of the rail and wheel impact force are playing an important role in the influencing factors on fatigue failure of the rail joint bolts. Due to this, the two bolts near the rail joints will to be fatigue failure almost earlier than others. That is one of the reasons why the bolts should be preloaded or replaced regularly.

Study on Fatigue Strength of Welding Joint in Wuhan Iron and Steel

2012 ◽  
Vol 538-541 ◽  
pp. 1492-1497
Author(s):  
Zhen Ping Fan ◽  
Xiao Wu ◽  
Qiang Li
Keyword(s):  
Finite Element ◽  
Fatigue Strength ◽  
Stress Concentration ◽  
Abrupt Change ◽  
Iron And Steel ◽  
Welding Joint ◽  
The World ◽  
Grouping Method ◽  
Weld Area ◽  
Distribution Of Stress

As abrupt change of the shape and elastic constant in the weld area occurs to the welding joint, there will be obvious stress concentration near the weld area when being loaded. Lifting and Lowering Method and Grouping Method prevailing in the world are applied to conduct an experiment about fatigue strength of a certain welding joint in Wuhan Iron and Steel and S-N curve is drawn in this paper based on the condition of nominal stress. In addition, the influence of weld size of the welding joint on the distribution of stress is studied through the calculation of finite element numeral value and experimental test. According to the factor of stress concentration, S-N curve is modified to provide the data support for the application of the welding joint and assessment of fatigue strength.

scholarly journals A Multi-Scale Submodel Method for Fatigue Analysis of Braided Composite Structures

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4190
Author(s):  
Jincheng Zheng ◽  
Peiwei Zhang ◽  
Dahai Zhang ◽  
Dong Jiang
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Fatigue Failure ◽  
Failure Criterion ◽  
Cell Model ◽  
Fatigue Analysis ◽  
Analysis Method ◽  
Shear Lag ◽  
Multi Scale ◽  
Meso Scale

A multi-scale fatigue analysis method for braided ceramic matrix composites (CMCs) based on sub-models is developed in this paper. The finite element shape function is used as the interpolation function for transferring the displacement information between the macro-scale and meso-scale models. The fatigue failure criterion based on the shear lag theory is used to implement the coupling calculation of the meso-scale and micro-scale. Combining the meso-scale cell model and the fatigue failure criterion based on the shear lag theory, the fatigue life of 2D SiC/SiC is analyzed. The analysis results are in good agreement with the experimental results, which proves the accuracy of the meso-scale cell model and the fatigue life calculation method. A multi-scale sub-model fatigue analysis method is used to study the fatigue damage of 2D SiC/SiC stiffened plates under random tension–tension loads. The influence of the sub-models at different positions in the macro-model element on the analysis results was analyzed. The results shows that the fatigue analysis method proposed in this paper takes into account the damage condition of the meso-structured of composite material, and at the same time has high calculation efficiency, and has low requirements for modeling of the macro finite element model, which can be better applied to the fatigue analysis of CMCs structure.

Numerical Investigation of Pressure-Cycling Induced Fatigue Failure of Wrinkled Energy Pipelines

2021 ◽  
pp. 1-38
Author(s):  
Navjot Singh ◽  
Sreekanta Das ◽  
Peter Song ◽  
Nader Yoosef-Ghodsi
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Internal Pressure ◽  
Fatigue Failure ◽  
Fatigue Loading ◽  
Element Model ◽  
Pressure Cycling ◽  
Concentration Factors ◽  
Fatigue Life Analysis ◽  
Stress Concentration Factors

Abstract Wrinkle defects can be complex pipeline deformities to assess and can present the potential to initiate a pipeline release incident as a result of fatigue failure due to pressure cycling, if not dealt with accordingly. Specifically, the stress distribution arising due to applied loads such as internal pressure can vary rapidly due to the complex shape along the wrinkle profile, which may introduce complexities in subsequent assessments such as fatigue life analysis. This paper presents a methodology using numerical simulation for evaluating stress concentration factors of wrinkle defects of varying geometries. A nonlinear finite element model is developed to evaluate stress concentration factors induced by wrinkle defects within steel pipelines subjected to internal pressure. Afterwards, data from full-scale laboratory tests for the wrinkled pipe specimens subjected to cyclic pressure fatigue loading is analyzed to evaluate stress concentration factors for comparable wrinkle profiles. Lastly, a comparison between the results of the stress concentration factors evaluated using finite element method and test data is provided, followed with a brief discussion of potential sources of discrepancies between results obtained from these methods.

Research on Analysis Method of Fatigue Strength for New Type Crushing Ripper Based on the Composite Load Spectrum

2014 ◽  
Vol 487 ◽  
pp. 378-384
Author(s):  
Feng Yi Lu ◽  
Xin Xin Liu ◽  
Ge Ning Xu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Strength ◽  
Strength Analysis ◽  
Analysis Method ◽  
Load Spectrum ◽  
Element Analysis ◽  
Structural Fatigue ◽  
The Finite Element Analysis ◽  
New Type

In view of the problem that new type crushing ripper installation of tamping equipment in circulation under the action of different load working multiple cases may occur structural fatigue damage, analysis of its force characteristic, establishment ripper rack compression bending component model, according to the working condition of the most unfavorable load combinations, using the allowable stress method to calculate structural fatigue strength; the combined effect of road load spectrum and vibrating load is also taken into consideration, then statics analysis and fatigue analysis of new type crushing ripper are calculated with the finite element analysis software Ansys Workbench. The results show that theoretical calculations are in accordance with the finite element analysis results, it evidences that the fatigue strength analysis method of crushing ripper is feasible and correct. It provides a reference for the anti-fatigue optimization design of new type crushing ripper, to guarantee its meet the operational requirements under of bad conditions.

Fatigue Strength Reliability Analysis of Diesel Connecting Rod Based on Stochastic Finite Element Method

1999 ◽  
Vol 121 (4) ◽  
pp. 741-745 ◽  
Author(s):  
C. Yi ◽  
W. Mingwu ◽  
T. Ling
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Fatigue Strength ◽  
Stress Analysis ◽  
Reliability Analysis ◽  
Fatigue Failure ◽  
Failure Criterion ◽  
Stochastic Finite Element Method ◽  
Stochastic Finite Element ◽  
Connecting Rod

In this paper, stress of a diesel connecting rod (CR) is analyzed by the perturbation stochastic finite element method (PSFEM). A fatigue failure criterion of a diesel CR is also put forward with Corten-Dolan fatigue cumulative damage theory. Based on fatigue failure criterion and the results of stochastic stress analysis, the advanced first order second moment (AFOSM) method is used for fatigue strength reliability analysis. It is shown that PSFEM is efficient and accurate in stochastic stress analysis by comparing with Monte-Carlo simulation. The analysis shows that the reliability of a certain type of diesel CR is 0.99917, which coincides with the statistical data from the factory. It is also found that operating parameters such as combustion peak pressure and engine rotary speed have the greatest influence on CR reliability because of the large variances and high stress response sensitivity.

Research of Fatigue Limit and Stress Concentration on Structural Steel with Double-Notches

2009 ◽  
Vol 419-420 ◽  
pp. 849-852
Author(s):  
Sheng Wu Wang ◽  
Shu Juan Sun ◽  
Ai Ling Wen ◽  
Wei Da Wang ◽  
Shinichi Nishida
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Fatigue Strength ◽  
Stress Concentration ◽  
Fatigue Limit ◽  
Three Dimensional ◽  
Fatigue Tests ◽  
Notched Specimen ◽  
Blind Hole ◽  
Element Method

The fatigue limit of parts and components that have the multi-notches is important data for the design and manufacture of machinery and traffic equipment which are operated under the high speed or pressure. In this paper the rotating bending fatigue tests have been carried out to investigate the fatigue limit of specimen with double-notch that is constructed of step and blind hole, and analyzed the effect of stress concentrations at the double-notched bottoms on the fatigue limits, using three-dimensional elastic finite element method. Firstly, the fatigue tests of 8 group specimens have been performed for examining the of fatigue limits of the single-notched specimen and double-notched specimen, respectively. Additionally, the stress field interactions between two stress fields by the blind hole notch and step are discussed using three-dimensional elastic finite element method. The main results obtained in this study are as follows: The fatigue limit of the double-notched specimen are down comparison with the fatigue limit of the single-notched specimen; the fatigue limit of the double-notch specimen is insensitive to distance between the blind hole and step for the low carbon structure steel with better ductility; for the high-strength steel, superposition and intensification of the stress concentration by the blind hole and step mutually may be avoided so that their adverse effects on the fatigue strength may be become to minimize, as take appropriate distance between the blind hole and step. The results are significant for the design of engineering design of the multi-notched parts, and the study of fatigue strength.

In vivo fracture of a reverse total shoulder replacement humeral tray: A case report

2016 ◽  
Vol 230 (12) ◽  
pp. 1141-1147
Author(s):  
Peter B MacDonald ◽  
Martin J Petrak ◽  
Trevor C Gascoyne ◽  
Eric Richard Bohm
Keyword(s):  
Finite Element ◽  
Case Report ◽  
Stress Concentration ◽  
Failure Analysis ◽  
Fatigue Failure ◽  
Small Radius ◽  
Shoulder Replacement ◽  
Reverse Total Shoulder Replacement ◽  
Reverse Total Shoulder

Failure analysis was performed for two humeral tray components which fractured in vivo after only 6 and 9 months. Implant retrieval analysis indicated that the components failed due to fatigue failure initiating from a small radius fillet at the interface of the trunnion and tray regions. Finite element simulations revealed the small radius fillet to have resulted in a large stress concentration and confirmed the possibility for fatigue failure in 6 months. The stress concentration caused by both the small radius fillet and the insufficient tray thickness contributed to the premature fatigue failure of the humeral trays.

scholarly journals Study on Fatigue Crack of Supporting Plate on Sonic Vibration Head

2014 ◽  
Vol 6 ◽  
pp. 106238
Author(s):  
Wang Yu ◽  
Lei Yuru ◽  
Liu Bao-lin ◽  
Li Zhi-jun
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Fatigue Crack ◽  
Stress Concentration ◽  
Fatigue Failure ◽  
Fatigue Testing ◽  
Steel Structures ◽  
Support Plate ◽  
Fatigue And Fracture ◽  
Supporting Plate

The supporting plate is one of the key parts of the sonic vibration head, and the regular fatigue and fracture make the support plate be one of the most venerably damaged units, resulting in huge loss in economy and security. After analyzing the loading states of the supporting plate on sonic vibration head, the mechanical stresses of three kinds of supporting plate under different operation load cases are simulated by the method of finite element method (FEM). The effects of stress of supporting plate are studied by means of fatigue testing on actual drilling processing. The results show that the steel structures fatigue failure is caused by stress concentration and unbalance. The optimal supporting plate structure is selected by the simulation and test.

scholarly journals Endurance testing and finite element simulation of a modified hip stem for integration of an energy harvesting system

2021 ◽  
pp. 095441192110216
Author(s):  
Hans-E Lange ◽  
Rainer Bader ◽  
Daniel Kluess
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Energy Harvesting ◽  
Fatigue Failure ◽  
Stress Level ◽  
High Stress ◽  
Worst Case ◽  
Total Hip ◽  
Piezoelectric Energy ◽  
Energy Harvesting System

Instrumented implants are a promising approach to further improve the clinical outcome of total hip arthroplasties. For the integrated sensors or active functions, an electrical power supply is required. Energy harvesting concepts can provide autonomous power with unlimited lifetime and are independent from external equipment. However, those systems occupy space within the mechanically loaded total hip replacement and can decrease the life span due to fatigue failure in the altered implant. We previously presented a piezoelectric energy harvesting system for an energy-autonomous instrumented total hip stem that notably changes the original implant geometry. The aim of this study was to investigate the remaining structural fatigue failure strength of the metallic femoral implant component in a worst-case scenario. Therefore, the modified hip stem was tested under load conditions based on ISO 7206-4:2010. The required five million cycles were completed twice by all samples (n = 3). Additionally applied cycles with incrementally increased load levels up to 4.7 kN did not induce implant failure. In total, 18 million cycles were endured, outperforming the requirements of the ISO standard. Supplementary finite element analysis was conducted to determine stress distribution within the implant. A high stress concentration was found in the region of modification. The stress level showed an increase compared to the previously evaluated physiological loading situation and was close to the fatigue data from the literature. The stress concentration factor compared to the original geometry amounted to 2.56. The assessed stress level in accordance with the experimental fatigue testing can serve as a maximum reference value for further implant design modifications and optimisations.

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