LIMIT CYCLE BEHAVIOR OF RAIL VEHICLES.

Significant practical problems are associated with the limit cycle behavior of rail vehicles. Although linear stability theory may be adequate for some vehicles, the presence of nonlinearities such as Coulomb friction in the vehicle suspension introduces the possibility of nested unstable and stable limit cycles. Determination of stability boundaries, or unstable limit cycles is of particular practical interest. Because realistic problems involve high order systems and multiple nonlinearities, approximation and numerical techniques are used in their solution. An overview of this rail vehicle stability problem, including vehicle description, solution techniques and typical limit cycle behavior is given.