Ride comfort of a high-speed train through the structural upgrade of a bogie suspension

This paper presents an approach to upgrade a bogie suspension (without a damaging) and thus to increase vibration isolation of a carbody in the infra frequency range, which is most important for ride comfort. The approach involves analysis of kinematic structure of the suspension׳s function-generating mechanism to detect sources of inefficiency within the supply and maintenance support of an existing design, as well as to predict the structural causes of a new design. A theory of the approach is presented. A survey of the typical suspensions is made; their kinematic structures are analyzed. The type and number synthesis of new candidates for the mechanism is illustrated to avoid undesirable structure redundancy in suspension design by the method of “negative” stiffness, which proved most promising. The utility of the approach is demonstrated through the upgrade of scaled simulated models and real suspensions.