Influence of Non-Uniform Railway Track Modulus on Wheel-Rail Contact Dynamic Forces and Wheel Tread Wear
| dc.contributor.advisor | Guler, Mehmet A. (Prof.) | |
| dc.contributor.author | Lovejoy, Mutswatiwa | |
| dc.date.accessioned | 2021-11-23T04:38:51Z | |
| dc.date.accessioned | 2023-11-04T15:17:27Z | |
| dc.date.available | 2021-11-23T04:38:51Z | |
| dc.date.available | 2023-11-04T15:17:27Z | |
| dc.date.issued | 2020-07 | |
| dc.description.abstract | The current trend of increased speeds and axle loads in the railway industry has led to accelerated wear of railway contact materials. This effect has brought with it new technological challenges including the monitoring and optimization of the wheel-rail interface parameters. For predictive maintenance purpose, railway vehicle wheel wear evolution models have been developed. These models are known to assume the wheel rotating on a rigid rail. However recent developments have found out that flexibility of the track plays an important role in wear evolution. On the other hand, track stiffness variation along the track is known to exist because of environmental conditions or transitions between slab and ballasted track or transition through railway level crossings, and it affects the track flexibility. The present research work investigates the influence of non-uniform track modulus and its spatial variation on the wheel-rail contact forces, stresses and wheel tread wear using dynamic explicit finite element analysis (FEA). The FE model consists of a quarter car running on a rail supported by three crossties. The modulus of elasticity of the crossties is calibrated to produce the actual strains in the rail during normal operation of a light rail, with a reference to Addis Ababa Light Rail Transit Service (AALRTS). In addition the crosstie modulus is used to resemble the total equivalent rail support system stiffness on the FE model. The rotating wheel is equipped with a dashpot suspension that supports the quarter railcar load. The stresses, forces, moments, contact areas, and slip velocities are extracted from the ABAQUS FEA model repetitively, at varying crosstie moduli ratio, using Python codes. These contact quantities are used to calculate the volume of material removal on the wheel tread using the Archard wear model. It was observed that an increase in crosstie modulus variation results in an increase of amplitudes of contact forces and the variations of their frequencies. Furthermore, high contact stresses were recorded at non-uniform track supports modulus. These factors influenced an increase in the volume of material removed on the wheel tread surface, at varying relative to uniform crosstie modulus. This research work intends to incorporate the spatial variation of the railway track stiffness into rail vehicle wheel tread wear prediction models. It leads to the development of better maintenance strategies and policies, which in-turn reduces the railway life cycle costs. | en_US |
| dc.identifier.uri | http://etd.aau.edu.et/handle/123456789/28838 | |
| dc.language.iso | en_US | en_US |
| dc.publisher | Addis Ababa University | en_US |
| dc.subject | Wear, Rolling Stock Maintenance | en_US |
| dc.subject | Track Infrastructure maintenance | en_US |
| dc.subject | Railroad Track Stiffness Spatial Variation | en_US |
| dc.subject | Track Stiffness | en_US |
| dc.subject | Life Cycle Cost | en_US |
| dc.subject | Contact mechanics | en_US |
| dc.subject | Track Stiffness/Modulus and Wheel-Rail Materials | en_US |
| dc.subject | wheel-rail interaction | en_US |
| dc.subject | explicit finite element analysis | en_US |
| dc.title | Influence of Non-Uniform Railway Track Modulus on Wheel-Rail Contact Dynamic Forces and Wheel Tread Wear | en_US |
| dc.type | Thesis | en_US |