Innovative design of a Twin Disc tribometer for wheel-rail contact analysis

Investigating and managing the wear in wheel-rail interactions is crucial for enhancing safety, reliability, and efficiency in railway systems while also reducing maintenance costs. Quantifying wear can be approached through various methods. Experimentally, tests may be conducted in the field or through simulated experiments; these may be carried out on different scales, which may range in scale from full-scale laboratory experiments to smaller-scale tests using rigs such as the "pin on disc", “ball on disc” or "twin disc" tribometers. This paper introduces a novel design concept for a twin-disc tribometer constructed using readily available components. The main novelty of the newly designed twin disc is that both the rail and wheel discs are machined to the actual scaled profile shapes. Nonetheless, as the Pascal's similitude model does not ensure the similarity of the contact patch area, because of the nonlinearities in the hertzian contact, the rail profile is slightly modified to keep a coherent scaling of the contact area, and normal load. This adjustment ensures the scaled model maintains an accurate representation of the contact area and normal load, addressing a critical aspect of the scaling process.