Papers by Author: Shi Jing Wu

Abstract: The nonlinear dynamic model of Ravingneaux compound planetary gear sets has been built. The model includes time-varying mesh stiffness of gears, backlash as well as comprehensive mesh errors nonlinearities. By introducing relative displacements of components as the new generalized coordinates, uniform nonlinear differential equations of compound planetary gear sets are built. Then the nondimensional dynamic differential equations are derived. The nonlinear differential equations have been solved utilizing ariable step size Gill method. By changing system nondimensional excitation frequency, monocycle anharmonic response, multiply periodic subharmonic response, quasi-periodic response and chaotic response are obtained. By means of time histories, phase-plane diagram, Poincare maps and power spectrum, various responses are compared and analyzed in detail.

Abstract: With the aiming of mathematically modeling dynamic behavior in latitudinal and vertical movements of the 6-axle locomotive, this paper introduces the Kalker’s Wheel-Rail Rolling Contact Theories and their implementation in multibody codes. This paper also highlights methodology for solving inhomogeneous linear second-order differential equations with MATLAB computer software aided. The calculation has reported that the dynamic behaviors of Diesel-Electric 6-axle locomotive are significantly demonstrated. The calculation has reported that the dynamic behaviors of Diesel-Electric 6-axle locomotive are significantly demonstrated the requirements on Rolling stock Dynamic behaviors of Vietnam Railways.

Abstract: Galloping of power transmission lines is a low frequency self-oscillation with large amplitude. The aerodynamic effect on each sub-conductor of 4-bundle conductor is different due to wake-flow-influence. In order to explore the reasons leading to galloping, a 3-D model for power transmission line is built. A two-node quadratic beam element in 3-D and a structure mass element are applied to establish the finite element model of iced 4-bundle conductor in ANSYS software. Then dynamic transient response calculations are made on this model. According to the results, difference in vibration of sub-conductors and frequency coupling of torsional and transverse vibration can be confirmed. The simulation results illustrate the wake-flow-influence effect and the coupled motions effect on galloping of 4-bundle conductor.