Ride comfort enhancement of the Indian railway vehicle using an optimized dynamic vibration absorber under stochastic track irregularities

Indian Railway vehicles are subjected to various excitation inputs due to errors in track gauge, alignment, cross-level, and vertical profile. These errors are vertical and lateral in nature; however, they induce severe vibrations in the vertical, lateral, roll, pitch, and yaw directions. In the present work, a 31-degree-of-freedom rigid-body model of an Indian Railway Integral Coach Factory vehicle with a multi-degree-of-freedom dynamic vibration absorber was developed to analyze the vertical, lateral, roll, pitch, and yaw vibrations simultaneously under stochastic track‑irregularity inputs. Initially, the parameters of the dynamic vibration absorber are selected without consideration of coupled motion. These parameters are then optimized to have an optimum ride comfort index for the vehicle carbody.