scholarly journals Fatigue Life Prediction for Semi-Closed Noise Barrier of High-Speed Railway under Wind Load

2021 ◽  
Vol 13 (4) ◽  
pp. 2096
Author(s):  
Xiaoping Wu ◽  
Ye Zhu ◽  
Lingxiao Xian ◽  
Yingkai Huang
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
High Speed ◽  
Time History ◽  
Wind Load ◽  
Fatigue Life Prediction ◽  
Driving Safety ◽  
Design Stage ◽  
Noise Barriers ◽  
Noise Barrier

The fatigue state of the semi-closed noise barrier directly affects driving safety, and replacement after damage leads to train delays and increased operating costs. It is more eco-friendly and sustainable to predict the fatigue life of noise barriers to reinforce the structure in time. However, previous life prediction methods provide a limited reference in the design stage. In this study, a novel fatigue life prediction method for noise barriers was proposed. The computational fluid dynamics and finite element model of the semi-closed noise barrier were established and subjected to simulated natural wind and train aerodynamic impulse wind loads to calculate the stress time-history on the noise barrier. Based on the rain flow counting method and Miner linear cumulative fatigue damage theory, the fatigue life of noise barriers in three Chinese cities was predicted. The results show that the fatigue life of the noise barrier is closely related to the wind conditions and train operation modes. Targeted reinforcement for noise barriers in different fatigue states can save materials and reduce maintenance workload. Moreover, the influence of wind load on the noise barrier was summarized, and engineering suggestions on prolonging the fatigue life of noise barriers were put forward.

Determination Method of a Proper Small-Load-Omitting Criterion Based on the Extreme Load

2013 ◽  
Vol 694-697 ◽  
pp. 278-283
Author(s):  
Zhi Qiang Xu
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
High Frequency ◽  
Life Prediction ◽  
Time History ◽  
Fatigue Life Prediction ◽  
Threshold Theory ◽  
Small Load ◽  
Extreme Load ◽  
Peak Over Threshold

A crucial step to obtain a reliable fatigue life prediction is to determine a proper small load threshold below which the cycles at small loads or stresses with high frequency causing little fatigue damage are truncated from the original load time history. By taking both the peak over threshold theory and the endurance limit threshold into account, a proper small load threshold is proposed in this paper. The optimal threshold should be high enough to remove the high-frequency small cycles and low enough to minimize the loss of the fatigue damage which maybe be truncated by the empirical small-load omitting threshold. Based on this proper threshold, the fatigue life prediction will be more reliable.

scholarly journals Fatigue life prediction and influencing factors analysis of mesh flexible spoke non-pneumatic tire

2021 ◽  
Vol 13 (10) ◽  
pp. 168781402110524
Author(s):  
Hongxun Fu ◽  
Xiaoxia Chen ◽  
Qiang Zhao ◽  
Zhen Xiao ◽  
Xuemeng Liang
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Optimization Design ◽  
Structural Parameters ◽  
Prediction Method ◽  
Simulation Method ◽  
Fatigue Life Prediction ◽  
Fatigue Performance ◽  
Driving Safety ◽  
Pneumatic Tire

A mesh flexible spoke non-pneumatic tire is designed to avoid tire burst and other hidden dangers in the traditional pneumatic tires, and improve driving safety. The purpose of this study is to explore the fatigue performance and fatigue life prediction method of the non-pneumatic tire and analyze the influence of structural parameters on the fatigue life of non-pneumatic tire. Based on the crack propagation method of energy release rate by J-integral, the fatigue life of the meshed flexible spoke non-pneumatic tire is predicted. Using numerical simulation method, the influence of key structural parameters, such as the curvature, unit angle and thickness of the lateral spoke and the tread thickness, on tire fatigue life is studied. The results show that the fatigue life prediction method proposed can be used to predict the fatigue life of flexible spoke non-pneumatic tire, and the fatigue life of non-pneumatic tire with flexible spoke can be improved by selecting appropriate structural parameters, which could provide some reference for the structural optimization design of the fatigue performance of the non-pneumatic tire.

scholarly journals Mitigation for Hawser‘s Short Fatigue Life on The Study of The Fatigue Life Prediction of Hawser in Single Point Mooring (SPM) at Tuban Fuel Terminal

2019 ◽  
Vol 63 (3) ◽  
pp. 5-12
Author(s):  
Ahmad Syafiul Mujahid ◽  
Keyword(s):  
Numerical Simulation ◽  
Fatigue Life ◽  
Life Prediction ◽  
Single Point ◽  
Time History ◽  
Fatigue Life Prediction ◽  
Fuel Oil ◽  
Mooring Lines ◽  
Tension Time ◽  
Outside Diameter

One of the vital components of SPM System is Mooring Hawser. Mooring Hawser is mooring lines that used to anchor the tanker ship that are berthed at Single Point Mooring (SPM) fuel terminal to loading or offloading the fuel oil. The incident of broken hawser unexpectedly due to short fatigue life that occurs on hawser when tanker ship that is anchored at SPM 150.000 DWT at Tuban Seas, East Java, Indonesia is the basis of this study for mitigation and replace of new hawser. This study calculates fatigue life of the hawser by using numerical simulation approach and Palmgren-Miner Methods. the hawser variation that conducted is only at the size of the outside diameter, namely: 0.144 m, 0.152 m, and 0.160 m. The material properties of the hawser in this study are Nylon Polyamide PA66. Numerical simulation consist of two steps: Hydrodynamics diffraction numerical simulation is used to obtain response (RAO) of tanker ship and SPM, and hydrodynamics time response numerical simulation is used to obtain effective hawser tension time history in 3600 second time simulation. By using the S-N Curve of Nylon Polyamide PA66 that is obtained from Jernej Klemenc, Andrej Wagner, and Matija Fadjiga (2011) as the basis to calculate fatigue life prediction of three variations in the outside diameter of the hawserwith Palmgren-Miner methods. The calculation result of new hawser fatigue life = 57.40536 Months or 4.718249 Years of Effective Berthing Time. The new hawser use outside diameter variation = 0.152 m to replace the previous hawser.

scholarly journals Fatigue life prediction of centrifugal fan blades in the ventilation cooling system of the high-speed-train

2020 ◽  
Author(s):  
Ning He ◽  
PengFei Feng ◽  
Zi Li ◽  
Li Tan ◽  
Lan Mo ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
High Speed ◽  
Cooling System ◽  
Research Result ◽  
Element Model ◽  
Fatigue Life Prediction ◽  
Centrifugal Fan ◽  
High Speed Train ◽  
Typical Structure

The centrifugal fan blades of the high-speed train ventilation and cooling system are subjected to cyclic loading which will shorten the life of fan blades. It could cause an accident of the high-speed-train in service. In this study, a modified method based on the nominal stress method was proposed and developed for the fatigue life prediction of centrifugal fan blades. The finite element model was firstly used to analyze the mode and the stress of fan blades based on the typical material property. The fatigue life was predicted based on the physical curve, using the Miner’s cumulative damage rule to calculate total damage. In order to verify the effectiveness of this method, the experimental tests were conducted on fan blades using a fatigue bench system, which were the typical structure of the ventilation cooling system of the high-speed-train. The damage mechanisms of blades was deduced from the fracture fractographs. The ventilation good correlation was achieved between the prediction model and the actual experimental results, testifying the practicability and effectiveness of this proposed method. Thus, the research result can reduce the probability of accidents caused by the fan blade damage and improve the reliability of the ventilation cooling system of the high-speed train.

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