Influence of Wheel-Rail Contact Point Changes on Force-Measuring Wheelset Measurement and the Compensation Method

［Objective］During train operation, there is random vibration in the wheelset, which causes position changes of the wheel-rail contact point, thereby affecting the measurement results of the wheel-rail force. To solve this problem, a measurement compensation method is proposed. ［Method］The influence of wheel-rail contact point position changes on the force-measuring wheel, and the compensation scheme for wheel-rail force measurement after wheel-rail contact point position change are introduced. The validity of the wheel-rail force measurement compensation scheme considering wheel-rail contact point position changes is verified through simulation analysis. ［Result & Conclusion］After adding the U.S Grade V track irregularity spectrum excitation, the maximum offset of the wheel-rail contact point position is 17.53 mm, and the maximum relative error of the vertical force reaches 22.85%; after adopting the proposed measuring compensation method, the maximum relative error of the wheel-rail vertical force decreases to 8.02%, and the measurement accuracy is significantly improved. After superimposing the sharp bend irregularity spectrum, the maximum derailment coefficient reaches 1.016 8, exceeding the allowable limit; the derailment coefficient calculated by the non-offset calibration coefficient is 0.347 7, and the derailment coefficient calculated with the proposed compensation method is 0.962 2, indicating that this method can accurately reflect better the train running safety status.