Study On The Load Spectrum Of The High-speed Train Axle And The Fretting Damage

The train axle is the key component of the Electric Motor Unit (EMU). With the successful development of the CRH380AL in China, the alternating load on bearings becomes more and more serious by the speed of 380km/h. At the same time, due to accumulated fretting damage on the axle press-fit parts, fatigue fracture may happen during the operation of the EMU, leading to severe accidents and economic loss.This paper researches on the load spectrum of the axles and damage on the axle press-fit parts, using the dynamic strain measurement and Finite Element Method (FEM).The approaches of the paper are stated as follows:1. The approaches to fixing up the strain gauges and arranging the bridge are proposed in this paper. Hypermesh and Ansys are used to analyze the model of wheel set. Then the load-strain transfer coefficient can be obtained by the load of the measuring points.2. We process the dynamic stress data derived from the intervals on the Beijing-Shanghai Highspeed Railway.The time history of the dynamic strain is transformed into the time history of the load by load identification. According to the previous research, load spectrums at the different speeds are shown in the paper.3. We analyze the relation between the load and the damage on the axle press-fit parts according to the load on the axles.4. With the principle of equivalent damage,we obtain the equivalent stress amplitude of 12 million km by stress spectrum with the different methods.According to the manufacturer's standards and regulations for fatigue limit of axle press-fit parts, we compare equivalent stress amplitude with fatigue limit to analyze the damage on the axle press-fit parts.5. From the perspective of axle size,we discuss measures and methods that how to reduce the fretting damage of axle press-fit parts measures and methods.