Fatigue strength analysis of bogie frames under random loads

Abstract

In this study, a method for analyzing the fatigue strength of a bogie frame under a random load was proposed. Based on the geometric features, a welded joint coordinate system was established to compute the stress components of each node in this coordinate system. With the influence of small amplitude cycles included, based on the corrected S–N curve and a method for calculating the equivalent constant amplitude stress, the node and comprehensive degree of utilization were calculated based on the anti-fatigue design grade of welded joints to evaluate the fatigue strength of a structure under a given lifespan. The FKM and International Institute of Welding methods were used to evaluate the fatigue strength of typical welded joints of a bogie frame. The characteristics of the node degree of utilization under different analytical methods were compared, and the results showed that when the time histories of the three stress components of the nodes had significant non-proportional features, the FKM method obtained conservative results. When the time histories of the three stress components of the nodes were synchronized, the criterion value specified by the International Institute of Welding method was the main factor affecting the distribution characteristics of the node degree of utilization. The analysis based on the International Institute of Welding method can effectively balance the lightweight design and reliability of the structure.

Multi-objective optimal design for the railway bogie frame system under stress and fatigue analysis

“…Seo et al [4] investigated the bogie frame's fatigue strength to explore the impact of a multiaxial load. An et al [5] analyzed the metro bogie frame's fatigue strength under random load. Lutema and Mohammedseid [6] estimated the bogie's fatigue life through uncertainty-parameter-based cumulative damage calculations.…”

Fatigue damage and reliability assessment of subway train bogie frames under operating conditions

“…The fatigue strength of bogie frames under random loads was investigated by introducing the elasticity of the car body and the bogie frame in a dynamic model of the vehicle system. [6][7][8] The dynamic load characteristics could be obtained on either the frequency domain or the time domain and the fatigue life of a bogie frame can be predicted numerically. 9 The influence of structural vibrations on the fatigue strength of a bogie frame was studied with the modal superposition method.…”