Fatigue
Mazuri Erasto Lutema; Awel Mohammedseid Momhur
Abstract
The most crucial parts that literally sustain the safety of railroad rolling stock from the subfloor are the wheels. However, during operation, several random parameters can impair their performance, resulting in the train's unsafety. These unpredictable characteristics can lead to fatigue failure, especially ...
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The most crucial parts that literally sustain the safety of railroad rolling stock from the subfloor are the wheels. However, during operation, several random parameters can impair their performance, resulting in the train's unsafety. These unpredictable characteristics can lead to fatigue failure, especially in a CHR2 high-speed train. This study aims to analyse the fatigue life of railway wheels for the CHR2 high-speed train due to different random parameters. Three scenarios with random parameters were considered: suspension system, passenger weight, and train speed. A 3D wheel model created by CAD and analyzed with finite element software ANSYS and nCode to validate the model by applying static force. A railway vehicle-track dynamics model with a 30t axle load using the vehicle-track dynamics theory. Then Monte Carlo simulations performed to produce random samples of sensitive parameters and analyze their effect distributions on wheel–rail contact under random wheel parameters. The findings demonstrate that the random parameters of the suspension system have more negative effects on fatigue life compared to random passengers’ weight and train speed, however, random passengers’ weight has a less negative impact compared to random suspension and passenger weight. But also, the dynamic results stress analysis showed that the random suspension system parameters have a high maximum stress compared to the stress obtained from random passengers’ weight and train speed. Moreover, the random suspension system parameters have high maximum stress compared to stress obtained from random passengers’ weight and train speed.
Pressure Vessels
A. R. Shahani*; H. Esmaili; A. Aryaei; S. Mohammadi; M. Najar
Abstract
In this paper, the dynamic simulation for a high pressure regulator is performed to obtain the regulator behavior. To analyze the regulator performance, the equation of motion for inner parts, the continuity equation for diverse chambers and the equation for mass flow rate were derived. Because of nonlinearity ...
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In this paper, the dynamic simulation for a high pressure regulator is performed to obtain the regulator behavior. To analyze the regulator performance, the equation of motion for inner parts, the continuity equation for diverse chambers and the equation for mass flow rate were derived. Because of nonlinearity and coupling, these equations are solved using numerical methods and the results are presented. Additionally, the dynamic analysis results consist of the output pressure change versus time, the displacement of the moving parts versus time, the regulator mass flow rate versus time and the output pressure versus mass flow rate in different controlling spring pre-loads. Furthermore, the sensitivity analysis is carried out and the main parameters affecting the regulator performance are identified. Finally, the results of the dynamic simulation are validated by comparing them with the experimental results.
