Wheel-rail contact force measurement. A comparison between distance laser and strain gauges measuring technology

Abstract

The development of this PhD thesis is focus on the wheel/rail contact force measurement on a 1 : 10 scaled railway vehicle. To that end, the author has designed and manufactured a dynamometric wheelset instrumented with several sensors for the direct measurement of forces applied on the instrumented wheel. Two di erent technologies have been used for the wheelset instrumentation: On the one hand, a set of strain gauges measure the radial strains experienced by the wheel-web when a lateral load is applied on the wheel. On the other hand, three high precision lasers have been installed on the axel that measure the lateral de ection experienced by the wheel due to the applied lateral loads. Normal contact forces are measured independently throughout the de ection experienced by the primary suspension. This is also measured with laser distance sensors. After being instrumented, the wheelset has been submitted to a calibration process. A calibration test bench where controlled loads can be applied to the wheelset has been also designed and manufactured. Finally the instrumented wheelset has been installed on the scaled vehicle and tested on a 5 inches wide scale track. The force measurements obtained in the experiments with both set of sensors have been compared with numerical results drawn from a computational model of the vehicle. A novel procedure to measure the track irregularities applied to the scaled track has been also include as part of this thesis. es dc.description.