Optimization of secondary suspension of three-piece bogie with bevelled friction wedge geometry

摘要

The multibody approach is utilized to investigate the dynamic characteristics of the modified friction wedge geometry in the secondary suspension of a freight wagon with three-piece bogies. In proposed design, each wedge is simulated with six Degrees of Freedom with corresponding geometry and inertial properties. The geometry of wedge as well as wedge angle, toe-in condition, and clearances between wedge and bolster/side frame are considered in modelling by point-plane contact technique. The contact model considers unilateral contact and non-smooth frictional forces. The three-dimensional model of the wedge simulates a frictional damping system that interacts with bolster in two separate inclined surfaces, longitudinally and horizontally. The optimum inclination angles are determined to reduce the carbody vertical acceleration and normal wheel-rail contact force subject to a track deviation for empty and loaded conditions. Moreover, the dynamic response of the freight wagon with optimal wedge geometry presents qualitative improvements regarding stability, hunting speed, and derailment probability in comparison with the conventional geometry of wedge.