Influence analysis of secondary suspension preload on the dynamic response of Y-25 bogie based on multibody simulations

Abstract

The freight bogie type Y-25 is the most used running gear in European freight wagons since its standardisation in 1967. Nonetheless, apart from several studies mostly focused on the primary suspension to improve the running characteristics, its design has barely changed over time. Up to date, there is rather little information and analyses related to the secondary suspension, limited to some standardised dimensional characteristics of its components, known as side bearers. In order to enhance the knowledge of these elements and their influence on the wagon operation, an analysis of the effect of the side bearers preload on different parameters related to the dynamic response of the wagon, such as the axle lateral force, wheel load transfer or bogie yaw velocity, is presented in this article for a Y-25 bogie. To this aim, a multibody model of a freight wagon with two Y-25 bogies is developed using Adams® and verified against the current normative for European freight wagons. The verified model is later subjected to varying suspension preloads, and the dynamicrelated parameters for different wagon carrying loads, speed and track layouts are analysed. The results obtained provide relevant information that contributes to increase the understanding of the secondary suspension elements in Y-25 bogies.