PSI - Issue 19

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

244

7

Temperature ( ℃ )

Max. 324 ℃

Fig. 9. Wheel temperature distribution during tread braking.

Contact pressure (MPa)

Front rim side

Flange side

Front rim side

Flange side

a

b

Max. 1332 MPa

Max. 1353 MPa

Wheel rolling direction

Wheel rolling direction

Fig. 10. Contact pressure distributions of the wheel model; (a) during tread braking; (b) after cooling.

σ r

σ z τ zr

σθ

τ r θ

τθ z

500

0

-500

-1000

Stress (MPa)

-1500

0

10

20

30

40

Moving distance (mm)

Fig. 11. Stress histories at the subsurface with tread braking and rolling contact.

3.3. Multiaxial stress evaluation The criteria for subsurface RCF crack initiation from internal defects are evaluated by applying the Findley model [10] similar to the previous study. Other models, such as McDiarmid [11] and Dang Van [12] have also been attempted. The McDiarmid and Dang Van models yield similar fatigue damage prediction results as the Findley model. The criterion for subsurface crack initiation is calculated from the relationship between the shear stress range