Modification optimization-based fatigue life analysis and improvement of EMU gear

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yong-Hua Li ◽  
Chi Zhang ◽  
Hao Yin ◽  
Yang Cao ◽  
Xiaoning Bai
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Engineering Practice ◽  
Analysis Method ◽  
Intelligent Algorithm ◽  
Transient Dynamic Analysis ◽  
Content Type ◽  
Gear Modification ◽  
Life Analysis ◽  
Fatigue Life Analysis

PurposeThis paper proposes an improved fatigue life analysis method for optimal design of electric multiple units (EMU) gear, which aims at defects of traditional Miner fatigue cumulative damage theory.Design/methodology/approachA fatigue life analysis method by modifying S–N curve and considering material difference is presented, which improves the fatigue life of EMU gear based on shape modification optimization. A corrected method for stress amplitude, average stress and S–N curve is proposed, which considers low stress cycle, material difference and other factors. The fatigue life prediction of EMU gear is carried out by corrected S–N curve and transient dynamic analysis. Moreover, the gear modification technology combined with intelligent optimization method is adopted to investigate the approach of fatigue life analysis and improvement.FindingsThe results show that it is more corresponded to engineering practice by using the improved fatigue life analysis method than the traditional method. The function of stress and modification amount established by response surface method meets the requirement of precision. The fatigue life of EMU gear based on the intelligent algorithm for seeking the optimal modification amount is significantly improved compared with that before the modification.Originality/valueThe traditional fatigue life analysis method does not consider the influence of working condition and material. The life prediction results by using the method proposed in this paper are more accurate and ensure the safety of the people in the EMU. At the same time, the combination of intelligent algorithm and gear modification can improve the fatigue life of gear on the basis of accurate prediction, which is of great significance to the portability of EMU maintenance.

Reliability assessment on automobile suspension system using wavelet analysis

2019 ◽  
Vol 10 (5) ◽  
pp. 602-611
Author(s):  
Airee Afiq Abd Rahim ◽  
Shahrum Abdullah ◽  
Salvinder Singh Karam Singh ◽  
Mohd. Zaki Nuawi
Keyword(s):  
Fatigue Life ◽  
Wavelet Decomposition ◽  
Reliability Assessment ◽  
Content Type ◽  
Low Level ◽  
Rural Road ◽  
Automobile Suspension ◽  
Life Analysis ◽  
Fatigue Life Analysis ◽  
High Level

Purpose The purpose of this paper is to focus on the reliability assessment on the basis of automobile suspension fatigue life using wavelet decomposition method. Design/methodology/approach The discrete wavelet transform (DWT) of automobile coil spring signal is implemented as a response to different road surfaces. A reliability analysis is applied to determine the potential of the wavelet implementation in fatigue life analysis. The signals used in this study are highway and rural road. Findings On the basis of the implementation of wavelet decomposition method, low-level decomposition replicates the original signals in comparison with high-level decomposition. The fatigue life of low-level decomposition lies in the 2:1 and 1:2 correlation graph. The percentage difference for mean cycle to failure presents low values for low-level decomposition, with 44.31 per cent for highway and 44.20 per cent for rural road. The percentage of difference for high-level decomposition is high. Originality/value The determination of fatigue life analysis by using the DWT method is suitable for low-level decomposition. High-level decomposition is considered noise that cannot be eliminated and does not contribute to the failure of the structure.

Fatigue life analysis of supercharged boiler based on the design by analysis method

2020 ◽  
Vol 188 ◽  
pp. 104217
Author(s):  
Qingpeng Zeng ◽  
Yanjun Li ◽  
Jianxin Shi ◽  
Guolei Zhang ◽  
Youdong Duan ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Analysis Method ◽  
Life Analysis ◽  
Fatigue Life Analysis

Microstructural, surface and fatigue analysis of stress peened leaf springs

2015 ◽  
Vol 6 (5) ◽  
pp. 589-604 ◽  
Author(s):  
Georgios Savaidis ◽  
Stylianos Karditsas ◽  
Alexander Savaidis ◽  
Roselita Fragoudakis
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Fatigue Life ◽  
Manufacturing Process ◽  
Treatment Process ◽  
High Strength ◽  
Content Type ◽  
Leaf Springs ◽  
Life Analysis ◽  
Fatigue Life Analysis

Purpose – The purpose of this paper is to investigate the fatigue and failure of commercial vehicle serial stress-peened leaf springs, emphasizing the technological impact of the material, the thermal treatment and the stress-peening process on the microstructure, the mechanical properties and the fatigue life. Theoretical fatigue analysis determines the influence of each individual technological parameter. Design engineers can assess the effectiveness of each manufacturing process step qualitatively and quantitatively, and derive conclusions regarding its improvement in terms of mechanical properties and fatigue life. Design/methodology/approach – Two different batches of 51CrV4 were examined to account for potential batch influences. Both specimen batches were subjected to the same heat treatment and stress-peening process. Investigations of their microstructure, hardness and residual stress state on the surface’ areas show the effect of the manufacturing process on the mechanical properties. Wöhler curves have been experimentally determined for the design of high-performance leaf springs. Theoretical fatigue analyses reveal the influence of every above mentioned technological factor on the fatigue life of the specimens. Therewith, the effectiveness and potential for further improvement of the manufacturing process steps are assessed. Findings – Microstructural analysis and hardness measurements quantify the decarburization and the degradation of the specimens’ surface properties. The stress-peening process causes significant compressive residual stresses which improve the fatigue life. On the other hand, it also leads to pronounced surface roughness, which reduces the fatigue life. The theoretical fatigue life analysis assesses the mutual effect of these two parameters. Both parameters cancel each other out in regards to the final effect on fatigue life. The sensitivity of the material and the potential for further improvement of both heat treatment and stress peening is appointed. Research limitations/implications – All quantitative values given here are strictly valid for the present leaf spring batches and should not be widely applied. The results of the present study indicate the sensitivity of high-strength spring steel used here to the various technological factors resulting from the heat treatment and the stress-peening process. In addition, it can be concluded that further research is necessary to improve the two processes (heat treatment process and the stress peening) under serial production conditions. Practical implications – The microstructure investigations in conjunction with the hardness measurements reveal the significant decrease of the mechanical properties of the highly stressed (failure-critical) tensile surface. Therewith, the potential for improvement of the heat treatment process, e.g. in more neutral and controlled atmosphere, can be derived. In addition, significant potential for improvement of the serially applied stress-peening process is revealed. Originality/value – The paper shows a systematic procedure to assess every individual manufacturing factor affecting the microstructure, the surface properties and finally, the fatigue life of leaf springs. An essential result is the quantification of the surface decarburization and its influence on the mechanical properties. The methodology proposed and applied within the theoretical fatigue life analysis to quantify the effect of technological factors on the fatigue life of leaf springs can be extended to any engineering component made of high-strength steel.

Fatigue Life Analysis of Large-Scale Liner Vibration Screener Based on ANSYS

2010 ◽  
Vol 37-38 ◽  
pp. 466-470 ◽  
Author(s):  
Yong Yan Wang ◽  
Xin Hua Fu ◽  
Tian Tong Guo ◽  
Li Chen ◽  
Hui Qing Mao
Keyword(s):  
Fatigue Life ◽  
Working Conditions ◽  
Theoretical Basis ◽  
Life Prediction ◽  
Large Scale ◽  
Local Stress ◽  
Analysis Software ◽  
Element Analysis ◽  
Life Analysis ◽  
Fatigue Life Analysis

Based on the theory of fatigue life prediction and by using the local stress-strain method and the material S-N curve of Q235 deduced by empirical formula; the fatigue was analyzed for the key parts of large-scale liner vibration screener by means of the general finite element analysis software, ANSYS. Thereby, the working conditions of force bearing, reliability and fatigue life-span of the key parts can be judged. The study will provide a theoretical basis for the design , manufacture, and installation of the large-scale liner vibration screener.

scholarly journals Impact Characteristics and Fatigue Life Analysis of Multi-Wire Recoil Spring for Guns

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Zhifang Wei ◽  
Xiaolian Zhang ◽  
Yecang Hu ◽  
Yangyang Cheng
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Life ◽  
Life Prediction ◽  
Fatigue Life Prediction ◽  
Helical Spring ◽  
Element Analysis ◽  
Life Analysis ◽  
Fatigue Life Analysis ◽  
The Impact

Recoil spring is a key part in automatic or semi-automatic weapons re-entry mechanism. Because the stranded wire helical spring (SWHS) has longer fatigue life than an ordinary single-wire cylindrically helical spring, it is often used as a recoil spring in various weapons. Due to the lack of in-depth research on the dynamic characteristics of the current multi-wire recoil spring in recoil and re-entry processes, the fatigue life analysis of the current multi-wire recoil spring usually only considers uniform loading and does not consider dynamic impact loads, which cannot meet modern design requirements. Therefore, this paper proposes a research method for fatigue life prediction analysis of multi-wire recoil spring. Firstly, based on the secondary development of UG, a three-wire recoil spring parameterized model for a gun is established. Secondly, ABAQUS is used to carry out a finite element analysis of its dynamic response characteristics under impact, and experimental verification is performed. Then, based on the stress-time history curve of the dangerous position obtained by finite element analysis, the rain flow counting method is used to obtain the fatigue stress spectrum of recoil spring. Finally, according to the Miner fatigue cumulative damage theory, the fatigue life prediction of the recoil spring based on the S-N curve of the material is compared with experimental results. The research results show that the recoil spring has obvious transient characteristics during the impact of the bolt carrier. The impact velocity is far greater than the propagation speed of the stress wave in the recoil spring, which easily causes the spring coils to squeeze each other. The maximum stress occurs at the fixed end of the spring. And the mean fatigue curve (50% survival rate) is used to predict the life of the recoil spring. The calculation result is 8.6% different from the experiment value, which proves that the method has certain reliability.

Fatigue Life Analysis Method of Upper-Hinge Joints of FPSO SYMS Based on Real-Time Proto-Type Monitoring Technique

2016 ◽  
Author(s):  
Wenhua Wu ◽  
Baicheng Lv ◽  
Wenyuan Li ◽  
Yanlin Wang ◽  
Qianjin Yue ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Friction Coefficient ◽  
Real Time ◽  
Mooring System ◽  
Analysis Method ◽  
Regional Stress ◽  
Monitoring Technique ◽  
Life Analysis ◽  
Fatigue Life Analysis

At present, the complexities of distributive characteristics in temporal and spatial domain of ocean environmental loading contribute to the difficulties of the fatigue life estimations of marine structures. In shallow water, soft yoke mooring system (SYMS) is considered to be the best mooring system, and has been widely used in oil development in the Bohai Bay and the Gulf of Mexico. Soft yoke mooring system establishes the mooring functions via the multi-dynamic mechanism of thirteen hinge joints. The accuracy of fatigue life of the hinge joints is important to ensure the safety of mooring system. The damage failure of hinge joints would cause great financial loss. In 2012, Dalian University of Technology set up a full coupled proto-type monitoring system which consisted of the four sub-monitoring systems, that is, ocean environmental parameters sub-system including wind, current and wave factor, motions and attitudes of the FPSO including six degree freedom of vessel motions, motions and the mooring force monitoring system of the mooring leg. The massive monitoring information is obtained by the integrated software with continuous. The present paper proposes a real-time fatigue life prediction method of upper hinge joint of SYMS based on the prototype monitoring technique. The friction parameter of hinge joints contact surface is increased in long-term service and reduced by adding lubricant. In the SYMS design phase, there is no effective analysis of the repeated friction parameter changes. The variations of friction coefficients caused by long-term cycle stress and maintenance are considered in the fatigue calculation. The stress distribution of hinge joints under design parameter is carried out by using ABAQUS. Through calculation and comparison, the equivalent stress and fatigue damage variable of KPA (Key Process Area, large deformation units and easy wear area) units in the condition of the friction coefficient is 0.15 (design parameter) and 0.95. We found that the friction coefficient change due to long-term service will speed up the fatigue failure of the hinge joints. The relationship between friction coefficients and KPA regional stress of mooring legs swinging angle are established through the finite element simulation. Through prototype monitoring software analysis the marine environment loading, structural response and KPA regional stress information, the abrasion of the hinge node and fatigue damage variable Dθμ can be real-time predicted. The present fatigue life analysis method based on monitoring technique exhibits good advantages and research value for the fatigue life estimation of offshore structure subject to wave induced motions.

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