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.

Durability Analysis of the Reduction Gear for High Speed Train Considering Driving Histories

2012 ◽  
Vol 586 ◽  
pp. 269-273
Author(s):  
Chul Su Kim ◽  
Gil Hyun Kang
Keyword(s):  
Fatigue Life ◽  
High Speed ◽  
Element Model ◽  
Rolling Stock ◽  
Reduction Gear ◽  
High Speed Train ◽  
Analysis Software ◽  
Tractive Effort ◽  
Durability Analysis ◽  
The Finite Element Model

To assure the safety of the power bogies for train, it is important to perform the durability analysis of reduction gear considering a variation of velocity and traction motor capability. In this study, two types of applied load histories were constructed from driving histories considering the tractive effort and the train running curves by using dynamic analysis software (MSC.ADAMS). Moreover, this study was performed by evaluating fatigue damage of the reduction gears for rolling stock using durability analysis software (MSC.FATIGUE). The finite element model for evaluating the carburizing effect on the gear surface was used for predicting the fatigue life of the gears. The results showed that the fatigue life of the reduction gear would decrease with an increasing numbers of stops at station.

Towards Truly Multiscale Simulation of Fatigue Processes in Metallic Structures

2009 ◽  
Author(s):  
John M. Emery ◽  
Jeffrey E. Bozek ◽  
Anthony R. Ingraffea
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Boundary Conditions ◽  
Finite Element Model ◽  
Life Prediction ◽  
Element Model ◽  
Multiscale Simulation ◽  
Fatigue Life Prediction ◽  
Length Scale ◽  
Metallic Structures

The fatigue resistance of metallic structures is inherently random due to environmental and boundary conditions, and microstructural geometry, including discontinuities, and material properties. A new methodology for fatigue life prediction is under development to account for these sources of randomness. One essential aspect of the methodology is the ability to perform truly multiscale simulations: simulations that directly link the boundary conditions on the structural length scale to the damage mechanisms of the microstructural length scale. This presentation compares and contrasts two multiscale methods suitable for fatigue life prediction. The first is a brute force method employing the widely-used multipoint constraint technique which couples a finite element model of the microstructure within the finite element model of the structural component. The second is a more subtle, modified multi-grid method which alternates analyses between the two finite element models while representing the evolving microstructural damage. Examples and comparisons are made for several geometries and preliminary validation is achieved with comparison to experimental tests conducted by the Northrop Grumman Corporation on a wing-panel structural geometry.

Fatigue Life Prediction Under Biaxial FALSTAFF Loading Using Statistical Volume Element Based Multiscale Modeling

2012 ◽  
Author(s):  
Jinjun Zhang ◽  
Kuang Liu ◽  
Aditi Chattopadhyay
Keyword(s):  
Fatigue Life ◽  
Root Mean Square ◽  
Life Prediction ◽  
Element Model ◽  
Fatigue Tests ◽  
Volume Element ◽  
Fatigue Life Prediction ◽  
Mean Square ◽  
Damage Criterion ◽  
Micro Cracks

This article presents the fatigue life prediction in a cruciform specimen of 2024-T351 aluminum alloy subjected to biaxial FALSTAFF loading. An energy- and slip-based multiscale damage criterion is developed to capture the fatigue crack formation in crystalline metallic materials. In these materials, there are two stages in crack initiation: nucleation of micro cracks and coalescence of micro cracks into major cracks. In the first stage, micro cracks generate from intermetallic particles and extend into surrounding grains. For the FCC crystalline structure, fatigue damage increments in four dependent slip planes are calculated and accumulated to measure micro crack. In the second stage, the micro cracks grow and coalesce into major cracks. Subsequently, a meso-statistical volume element model is developed to represent the microstructure of the material. Finally, a root mean square method is introduced to take into account FALSTAFF loading. Using the root mean square (RMS) method, the loading history for tests is analyzed to determine the RMS maximum and minimum stresses. The multiscale damage criterion, statistical volume element and RMS method were validated using previously conducted fatigue tests on cruciform samples. The fatigue life and crack direction predicted using the developed model correlate well with the experiments.

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.

Vehicle Frame Fatigue Life Prediction Based on Finite Element and Multi-Body Dynamic

2011 ◽  
Vol 141 ◽  
pp. 578-585 ◽  
Author(s):  
Si Hong Zhu ◽  
Zhi Jin Xiao ◽  
Xiao Yan Li
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Life Prediction ◽  
Element Model ◽  
Fatigue Life Prediction ◽  
Influence Coefficient ◽  
Loading History ◽  
Pavement Condition ◽  
Multi Body ◽  
Body Dynamic

To accurately predict the fatigue life of vehicle frame, MBS and FEM were integrated. A full multi-body dynamic model was established first, according to the spectrum of road surface which simulate the china’s pavement condition, loading history at 11 critical positions was calculated. Then the stresses influence coefficient was calculated in finite element model which establish in ANSYS. At the same time, according to the frame material’s S-N curve and character of the frame, the frame’s S-N curve was received. Finally, based quasi-static stress analysis, the frame structure’s fatigue life was predicted by using MSC-FATIGUE. The fatigue analysis results were reasonable and could be the foundation for the research about lightening the structure of the frame.

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