EXPERIMENTAL INVESTIGATIONS ON THE BEHAVIOR OF A POINT FIXED IN A WHEEL OR RAIL STRUCTURE COMPARED WITH A POINT FIXED RELATIVE TO THE CONTACT ZONE

A special measuring technique has been developed based on a Laser-Dopp ler-Vibrometer carried along with the bogie. The investigations were c arried out on a wheel/rail model in a scale factor 1:4. The set-up use d allows measurement of the vibrational behavior of the two substructu res, wheel and rail, near the contact point during the rolling process in a model frequency range up to 5 kHz. The comparison with results o f simultaneously performed conventional measuring techniques gives a n ew insight into the differences of the structure-borne sound behavior between a point fixed relative to the contact zone and a fixed point o n the wheel, or on the rail, respectively, The measured tread roughnes s, together with the point mobilities of wheel and rail, allows a pred iction based on a simple rolling model, the so-called Remington model. The disagreement between the calculated and the measured results is d iscussed. (C) 1997 Elsevier Science Ltd.