Experimental detection of modal interaction in the non-linear vibration of a hinged–hinged beam

The geometrically non-linear vibration of an aluminium beam hinged at both ends is investigated experimentally. The beam is excited transversely with a harmonic excitation and the amplitudes of the first and higher harmonics are analyzed at different points in order to detect the modes involved in the motions. It is demonstrated that internal resonances occur between the first and higher order modes, as well as between the second and higher order modes.