Nonlinear In-service Model Of A Hydraulic Yaw Damper And Its Influence On The Dynamics Of An Electriec Locomotive

Nonlinear modeling of the in-service performance of hydraulic yaw damper used in an electric locomotive is conducted in this work, and the influence of damper in-service parameter variations on the locomotive dynamics is also predicted. Differing from the traditional single damping element model or Maxwell model, a new nonlinear model concept focus on the in-service performance of the hydraulic yaw damper is suggested, the model includes three elements:an effective serial stiffness, a small clearance and a hydraulic damping. On guide of the concept, a more detailed nonlinear parametric model of the yaw damper is built and the model is validated by bench test. Finally, the influence of in-service parameter variations on the damping performance of the yaw damper is predicted.Both mathematical and MBS modeling of an electric locomotive dynamincs are performed, and the influence of damper in-service parameter variations on the locomotive dynamics is fully predicted using the validated MBS model. Study results show that: both the effective serial stiffness and the small clearance have great impact on the reduction of critical speed, the influence to ride comfort is also considerable, but they have almost no influence on the curve negotiability.The in-service model concept and pertinent conclusions suggested by this work can be used in both the damper optimization and rail vehicle suspension dynamic design. The establishment of an enginnering mantianence standard to effectively control the serial stiffness and the small clearance is anticipated.