An inverse structural filter method for wheel-rail contact forces identification of railway vehicles

The safety and stability of railway vehicle operations are closely related to the wheel-rail contact dynamic forces. For actual operating conditions, wheel-rail contact forces of railway vehicle are very difficult to directly measure. Based on a discrete time and state space representation of the dynamics, a time-domain identification method for dynamic loads is proposed, which is named an inverse structural filter (ISF) method. Taking the structural response data as input, the forces can be predicted for non-minimum phase and non-collocated structure. The advantage of the method is that it solves the difficulties of load identification caused by the instability of non-collocated inverse system. Considering railway vehicle as the research object, accelerations of axle box as input conditions, 10 degrees of freedom vertical vibration model and 17 degrees of freedom horizontal vibration model are established, respectively. The vertical and horizontal wheel-rail forces are identified. The inverse results are compared with SIMPACK simulation results which have the same kinetic parameters. The results indicate that the vertical and horizontal wheel-rail forces have the same trend with SIMPACK simulation results, and have a strong correlation. The acceleration vibration response of the vehicle's axle box is identified by a set of measured vertical acceleration and vertical displacement responses through a rolling and vibrating test-bed in TPL, and compared with the measured results, the correlation coefficient is strongly correlated whose value is as high as 0.9756. The inverse model has high inverse accuracy, and can be used for monitoring the running train wheel-/rail contact forces. © 2019, Nanjing Univ. of Aeronautics an Astronautics. All right reserved.