Summary
This study evidence that the resonant phase lags found numerically and analytically for single-degree-of-freedom systems in Volvert et al. cannot always be extended to the multi-degree-of-freedom case. Indeed, the potential interactions between primary and secondary resonances have a direct influence on the evolution of the phase lag of the studied harmonic. A phase lag that is a combination of carefully selected harmonics, should be considered to remove the influence of the other harmonics.
