Inertance-Integrated Primary Suspension Optimisation on an Industrial Railway Vehicle Model

The task of reducing track and wheel wear in the railway industry is one of particular financial importance. Previous studies into how the use of the passive device (the inerter) can benefit passenger comfort and track wear suggest a potential for large improvements. However, the models employed were heavily simplified. This paper focuses on the systematic optimisation of a fully nonlinear industry standard VAMPIRE® model, including inertance-integrated primary lateral suspensions, with the aim of reducing the Primary Yaw Stiffness (PYS). A reduced PYS will decrease the curving forces, which in turn reduces the generation of Rolling Contact Fatigue at the wheel and rail interface and also the Track Access Charge (TAC). Co-optimisation is carried out using the MATLAB® Optimisation Toolbox and VAMPIRE®, and several beneficial inertance-integrated hydraulic bush layouts are identified using a network-synthesis-based approach. It is shown that implementing these inertance-integrated layouts in the primary lateral suspension can allow the PYS to be decreased by 50%, whilst also improving ride comfort at the two most critical speed and conicity combinations (by up to 18%), without significantly compromising it in less critical cases. This 50% reduction in PYS will reduce the TAC by 10%. The performances with beneficial designs using nonlinear conicity data are assessed, as well as on curved and twisted track.