Vertical dynamic studies of an Indian railway vehicle moving on a straight track

This paper presents numerical simulation and experimental studies of the vertical dynamic behaviour of a typical Indian railway vehicle of the Alternating Current/Electrical Multiple Unit /Trailer (AC/EMU/T) type running on broad gauge track. Linear governing equations of motion of the vehicle, modeled as a 10 degree of freedom (dof) rigid body, have been solved and natural frequencies determined. Dynamic response studies were carried out in the time domain for the vehicle moving on a straight track with different irregularities of the track and wheel, such as wheel flat, welded joint defects and average vertical profile (AVP), imparted as excitation forces through Hertzian springs connected to the vehicle/track interface. The behaviour of the vehicle has been compared for air spring and coil spring as secondary suspension. The ride dynamic performance of the vehicle has been evaluated in terms of Sperling's ride indices for both ride comfort and ride quality at different speeds. Extensive experiments were carried out and analytical responses were found to compare well with experimental results. © Civil-Comp Press, 2010.