Nonlinear dynamics of ball vibration absorber considering stability, stationarity and rolling-condition boundaries

The paper presents a detailed nonlinear analysis of a ball vibration absorber (BVA), which consists of a harmonic oscillator with a spherical cavity and a rolling ball as an absorber. Frequency response curves are calculated using the harmonic balance method and pseudo arc length continuation, and stability is assessed using stability analysis applied to modulation equations. This is particularly important at higher excitation amplitudes where the modulation equations provide information on the presence of strongly modulated response regimes. Codimension-2 continuation is used to identify the onset of instability and non-stationary regions with respect to all key design parameters. The study highlights the critical role of the rolling and contact conditions in maintaining the validity of the solution and provides conditions for their satisfaction. The results provide valuable insights into the non-linear dynamic behaviour of the BVA, revealing its effectiveness in vibration reduction and its limitations due to parameter selection and design constraints.