NON-LINEAR RESPONSE OF A POST-BUCKLED BEAM SUBJECTED TO A HARMONIC AXIAL EXCITATION

An experimental investigation of the non-linear response of a clamped–sliding post-buckled beam subjected to a harmonic axial load is presented. Two types of resonances are considered: fundamental and subharmonic. The data demonstrate several non-linear phenomena including period-doubling sequence bifurcation, period-three, and chaotic motion. In addition, the effect of damping on the dynamic instability of the post-buckled beam is investigated. The regions of instability and chaotic response are shown for different damping levels. The resulting locus of instability of the periodic solutions in the amplitude–frequency parameter space provides valuable information on the overall dynamic behavior of the system. The qualitative changes can be observed when either the frequency or the amplitude of excitation is varied across a bifurcation curve. The measured data are illustrated through time histories, phase plots, Fourier spectra, and Poincare sections.