Analysis and enhancement of torsional vibration stopbands in a periodic shaft system

The band structure and the enhancement of stopbands in a periodic shaft are investigated. The band structures created by a hard ring and a locally resonant (LR) ring are studied first. A uniform method for analysing the band structures of periodic shafts with various attached structures is proposed. Furthermore, the enhancement of the stopbands is discussed. The properties of a shaft with a hard ring and an LR ring in different positions are studied, and a wide, combined gap is created at low frequencies. Additionally, continuous beams are also introduced to enhance the stopbands. Some helpful methods for analysis, prediction and increasing the width of stopbands in a periodic shaft system are provided.