Fatigue life estimation of MD36 and MD523 bogies based on damage accumulation and random fatigue theory

2009 ◽  
Vol 23 (8) ◽  
pp. 2149-2156 ◽  
Author(s):  
Davood Younesian ◽  
Ali Solhmirzaei ◽  
Alireza Gachloo
Keyword(s):  
Fatigue Life ◽  
Damage Accumulation ◽  
Life Estimation ◽  
Fatigue Life Estimation ◽  
Random Fatigue

Random Fatigue Failure of MD36 and MD523 Bogie Frames Due to Rail Corrugations

2008 ◽  
Author(s):  
Davood Younesian ◽  
Ali Solhmirzaei ◽  
Alireza Gachloo ◽  
Ebrahim Esmailzadeh
Keyword(s):  
Fatigue Life ◽  
Time History ◽  
Random Excitation ◽  
Fe Model ◽  
Life Estimation ◽  
Random Loads ◽  
Power Spectral ◽  
Fatigue Life Estimation ◽  
Rail Irregularities ◽  
Random Fatigue

Bogies are one of the multifunctional parts of trains which are extremely subjected to random loads. This type of oscillating and random excitation arises from irregularities of the track including rail surface corrugation, rail joints, variance in super-elevation, and also wheel imperfectness like wheel flats and unbalancy. Since most of the pre-mentioned sources have random nature, a random based theory should be applied for fatigue life estimation of the bogie frame. Two methods of fatigue life estimation are investigated in this paper. The first approach which is being implemented in time domain is based on the Damage Accumulation (DA) approach. Using Monte-Carlo simulation algorithm, the rail surface roughness is generated. Finite Element (FE) model of the bogie is subjected to the generated random excitation and the stress time history is obtained and then the fatigue life is estimated using the rain-flow method. In the second approach the fatigue life is estimated in frequency domain. Power Spectral Density (PSD) of the stress is obtained using FE model of the bogie and the fatigue life is estimated using Rayleigh technique in random fatigue theory. A comprehensive parametric study is carried out and effects of different parameters like train speeds and level of the rail irregularities on the fatigue life are investigated.

Model of Fatigue Damage Accumulation

2014 ◽  
Vol 598 ◽  
pp. 51-56 ◽  
Author(s):  
Józef Drewniak ◽  
Jacek Rysiński
Keyword(s):  
Stress Intensity Factor ◽  
Fatigue Life ◽  
Stress Intensity ◽  
Boundary Element Method ◽  
Fatigue Damage ◽  
Damage Accumulation ◽  
Gear Teeth ◽  
Life Estimation ◽  
Fatigue Life Estimation ◽  
Fatigue Damage Accumulation

In this paper, the analytical method of fatigue life estimation of gear teeth is proposed. The computational model of fatigue damage accumulation was built using the adequate NASGRO 2/3 formula, moreover Formans and Paris-Erdogans laws were utilized for comparison. The ranges of stress intensity factor were determined using the boundary element method.

Load Spectrum Compiling and Fatigue Life Estimation of the Automobile Wheel Hub

2020 ◽  
Vol 13 ◽  
Author(s):  
Xintian Liu ◽  
Yang Qu ◽  
Xiaobing Yang ◽  
Yongfeng Shen
Keyword(s):  
Fatigue Life ◽  
High Speed ◽  
Two Dimensional ◽  
Load Spectrum ◽  
One Dimensional ◽  
Life Estimation ◽  
Load Spectra ◽  
Fatigue Life Estimation ◽  
Program Load Spectrum ◽  
Program Load

Background:: In the process of high-speed driving, the wheel hub is constantly subjected to the impact load from the ground. Therefore, it is important to estimate the fatigue life of the hub in the design and production process. Objective:: This paper introduces a method to study the fatigue life of car hub based on the road load collected from test site. Methods:: Based on interval analysis, the distribution characteristics of load spectrum are analyzed. The fatigue life estimation of one - dimensional and two - dimensional load spectra is compared by compiling load spectra. Results:: According to the S-N curve cluster and the one-dimensional program load spectrum, the estimated range fatigue life of the hub is 397,100 km to 529,700 km. For unsymmetrical cyclic loading, each level means and amplitude of load were obtained through the Goodman fatigue empirical formula, and then according to S-N curve clusters in the upper and lower curves and two-dimensional program load spectrum, estimates the fatigue life of wheel hub of the interval is 329900 km to 435200 km, than one-dimensional load spectrum fatigue life was reduced by 16.9% - 17.8%. Conclusion:: This paper lays a foundation for the prediction of fatigue life and the bench test of fatigue durability of auto parts subjected to complex and variable random loads. At the same time, the research method can also be used to estimate the fatigue life of other bearing parts or high-speed moving parts and assemblies.

Notch fatigue life estimation of Ti-6Al-4V

2021 ◽  
Vol 120 ◽  
pp. 105098
Author(s):  
Camilla Ronchei ◽  
Sabrina Vantadori
Keyword(s):  
Fatigue Life ◽  
Life Estimation ◽  
Fatigue Life Estimation

An Investigation of Cyclic Transient Behavior and Implications on Fatigue Life Estimates

1997 ◽  
Vol 119 (2) ◽  
pp. 161-170 ◽  
Author(s):  
Yanyao Jiang ◽  
Peter Kurath
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Cyclic Hardening ◽  
Transient Behavior ◽  
Fatigue Tests ◽  
304 Stainless Steel ◽  
Deformation History ◽  
Life Estimation ◽  
Fatigue Life Estimation ◽  
Track Deformation

Current research focuses on proportional cyclic hardening and non-Massing behaviors. The interaction of these two hardenings can result in the traditionally observed overall softening, hardening or mixed behavior exhibited for fully reversed strain controlled fatigue tests. Proportional experiments were conducted with five materials, 304 stainless steel, normalized 1070 and 1045 steels, and 7075-T6 and 6061-T6 aluminum alloys. All the materials display similar trends, but the 304 stainless steel shows the most pronounced transient behavior and will be discussed in detail. Existing algorithms for this behavior are evaluated in light of the recent experiments, and refinements to the Armstrong-Frederick class of incremental plasticity models are proposed. Modifications implemented are more extensive than the traditional variation of yield stress, and a traditional strain based memory surface is utilized to track deformation history. Implications of the deformation characteristics with regard to fatigue life estimation, especially variable amplitude loading, will be examined. The high-low step loading is utilized to illustrate the effect of transient deformation on fatigue life estimation procedures, and their relationship to the observed and modeled deformation.

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