Analysis of the Transferability of the Systematic Error of Pressure Measurement Films Under Hertzian Conditions to Wheel-Rail Normal Contact

• Applicant: Professor Dr. Christian Schindler
• Subject Area: Engineering Design, Machine Elements, Product Development
• Term: from 2020 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 441889189

Contact bodies represent the basis of numerous machine elements in mechanical engineering and play a critical role regarding functional and often safety requirements in several applications. This statement applies especially to conventional rail vehicles, since the wheel-rail contact surface is the only mechanical interface between vehicle and track, which reacts support, guiding, driving and braking forces. A sound knowledge of the shape and dimensions of the contact patch, as well as its stress and strain state, is hence required. Although computer-aided calculations provide a good insight into the properties of the resulting contact surface, these are not conclusive without appropriate experimental validation. However, no method for the experimental determination of wheel-rail contact surfaces has established itself yet.Nevertheless, based on the long-standing knowledge acquired at the current and previous chair of the applicant, it can be stated that using commercially available pressure measuring film is a serious possibility for experimental contact surface characterization, provided that the systematic measurement error is known.In the context of this project, the transferability of the measurement error of pressure measurement films, which has only been determined for analytically computable bodies, to the actual wheel-rail normal contact is to be investigated. Based on the findings of another project, the material parameters of existing film models are to be adjusted by means of design of experiments in order to reproduce the known systematic deviation. Later, these film models shall be implemented in numerical wheel-rail models. The contact surfaces obtained from the simulation of this scenario are then to be validated by comparison with experimental observations with actual wheel-rail-profile combinations.

• DFG Programme: Research Grants