  In this work, we show that a recently proposed method for experimental
nonlinear modal analysis based on the extended periodic motion concept is well
suited to extract modal properties for strongly nonlinear systems (i.e. in the
presence of large frequency shifts, high and nonlinear damping, changes of the
mode shape, and higher harmonics). To this end, we design a new test rig that
exhibits a large extent of friction-induced damping (modal damping ratio up to
15 %) and frequency shift by 36 %. The specimen, called RubBeR, is a
cantilevered beam under the influence of dry friction, ranging from full stick
to mainly sliding. With the specimen's design, the measurements are well
repeatable for a system subjected to dry frictional force. Then, we apply the
method to the specimen and show that single-point excitation is sufficient to
track the modal properties even though the deflection shape changes with
amplitude. Computed frequency responses using a single nonlinear-modal
oscillator with the identified modal properties agree well with measured
reference curves of different excitation levels, indicating the modal
properties' significance and accuracy.
