Perpustakaan Digital ITB

Wheel flats generate transient wheel–rail impacts that increase dynamic contact forces and induce localized material response in railway wheels. Previous multibody dynamics studies on similar train models have described the global vibration response, but they could not resolve contact force, stress distribution, and plastic strain inside the wheel. This study develops a finite element model to evaluate the effects of operating speed and flat length on impact force, von Mises stress, and Equivalent Plastic Strain (PEEQ). The model was developed in Abaqus/Standard using a TB1014 wheel and UIC 54 rail. Dynamic implicit analysis was employed with connector elements for the suspension and rail pad, CIN3D8 infinite elements at the rail ends, and strain-rate dependent plasticity for the wheel steel. The model was validated using theoretical normal contact force, Hertzian contact area, and numerical stability based on the ALLAE/ALLIE ratio. Simulations were performed for flat lengths of 0, 20, 40, and 60 mm at operating speeds of 20, 40, 80, and 120 km/h. The results show that impact force increases with wheel flat length, while operating speed produces a non-monotonic response. The highest impact force, 250,417 N, occurs for the 60 mm flat at 40 km/h. All wheel flat cases produce von Mises stresses above the 733.1 MPa yield strength, with maximum stress reaching 1,049.53 MPa. The highest PEEQ is 0.0443 and occurs for the 60 mm flat at 40 km/h. Stress and PEEQ concentrations appear in the subsurface region, indicating a critical zone that may be susceptible to rolling contact fatigue related damage under repeated impacts.