Nonlinear damping quantification from phase-resonant tests under base excitation

The present work addresses the experimental identification of amplitude-dependent modal parameters (modal frequency, damping ratio, Fourier coefficients periodic oscillation). Phase-resonant testing has emerged as an important method for this task, it substantially reduces amount data required compared to conventional frequency-response at different excitation/response levels. In case shaker-stinger excitation, applied excitation force is commonly measured in order quantify ratio from phase-resonant test data. base however, challenging or impossible measure. we develop original quantification tests. It relies solely on response measurement; avoids need resort measurement. key idea estimate power provided by distributed inertia imposed motion. We both a model-free and model-based variant method. validate developed first virtual experiments friction-damped geometrically nonlinear system, then physical experiment involving thin beam clamped ends via bolted joints. conclude that highly robust provides high accuracy already reasonable number sensors.