Review of Research on Loading, Fatigue Damage, Remaining Service Life, and Technical Diagnostics of Electric Locomotive and Electric Multiple-Unit Bogie Frames

This article reviews existing research on loading conditions, fatigue damage, remaining service life, and technical diagnostics of bogie frames used in electric locomotives and electric multiple units (EMUs). Particular attention is paid to the effects of static and dynamic loads, cyclic stresses, vibration, and operational conditions on the structural integrity and fatigue resistance of bogie frames. The review examines commonly used approaches to stress analysis, fatigue life assessment, structural reliability evaluation, and residual service life prediction, including analytical calculations, finite element analysis, experimental testing, and numerical simulation. It also considers modern technical diagnostic methods, such as non-destructive testing, strain and vibration measurements, and condition monitoring, which support the detection of cracks, material degradation, and other structural defects.