PSI - Issue 19

T. Kato et al. / Procedia Structural Integrity 19 (2019) 238–248 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 1. Finite element analysis model.

Fig. 2. Contact surface profile of the finite element analysis model.

2.2. Finite element analysis conditions

Heat transfer and thermal stress analyses simulating wheel heat treatment are first performed. A heat transfer coefficient equivalent to water-cooling is applied to the tread surface in the quenching step of the heat transfer analyses to calculate the wheel temperature distributions. Subsequently, the thermal stress analyses are conducted by importing the temperature distributions obtained via the heat transfer analyses to calculate the residual stresses of the heat treatment. Elements of tread, front and back rim surface are eliminated after the heat treatment analyses to simulate the machining processes. Conditions of these analyses are the same between three different wheel diameters. Wheel-rail contact analyses are performed after importing the residual stresses of the heat treatment and the machining. The contact positions between the wheel models and the rail models are shown in Figure 3. There are three positions: flange side, tread center and front rim side. The wheel model positions are adjusted to make the center of the contact area coincide with the above contact positions. The analysis conditions are shown in Figure 4. Table 1 lists the applied vertical loadings and the maximum contact pressures calculated by the Hertzian theory of each wheel diameter. The vertical loadings correspond to a half of the maximum axle loads in the AAR specification. B38 and H36 wheels have almost the same contact pressure; however, J33 wheel has a lower contact pressure than the other two wheels.