A multi-stage high-speed railroad vibration isolation system with “negative” stiffness

The intensity of mechanical vibrations generated by a moving train increases at high speeds. Conventional railroad vibration isolation systems are either insensitive or inefficient in the infra-low frequency range, which is the range most hazardous to humans. In this work, an approach for upgrading a multi-stage system for engineers, crew, passengers, and people living near railroads is presented. The approach involves the design of geometrically similar redundant mechanisms with “negative” stiffness that could be compactly inserted into all system stages without degrading structure and safety. The approach is implemented in the design of seat suspensions. Finally, a concept relevant to the design of mechanisms for vehicle spring hangers and track bed elements is discussed in terms of the dimensional analysis.

► Protection against the vibrations generated by passing high-speed trains.
► Railroad vibration isolation system can be improved in the broad-band using the proposed approach.
► Approach consists in the generation of “negative” stiffness in each stage of the system.
► Chance with reference to upgrading car truck or locomotive bogie spring hangers.