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

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.

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.

Fatigue life analysis of shot-peened bearing steel

2012 ◽  
Vol 26 (6) ◽  
pp. 1747-1752 ◽  
Author(s):  
Sang-Jae Yoon ◽  
Jung-Hoon Park ◽  
Nak-Sam Choi
Keyword(s):  
Fatigue Life ◽  
Bearing Steel ◽  
Life Analysis ◽  
Fatigue Life Analysis
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