This study examined the vibrations of a hinged-free nonlinear beam placed on a nonlinear elastic foundation. The authors found
that specific combinations of an elastic modulus in the elastic foundation resulted in 1:3 internal resonances in the first and second modes of
the beam. This prompted adding a dynamic vibration absorber (DVA) on the elastic beam in order to prevent internal resonance and suppress
vibrations. When the DVA was placed at the free end of the beam, the boundaries were time dependent. Thus, a shifting polynomial function
was used to convert the nonhomogeneous boundary conditions into homogeneous boundary conditions. The authors analyzed this nonlinear
system using the method of multiple scales (MOMS). Fixed-point plots were also used to facilitate the observation of internal resonance. This
made it possible to study the influence of nonlinear geometry and nonlinear inertia associated with the vibration of the elastic beam.
The authors also examined the combination of optimal mass ratio and elastic modulus for the DVA in order to prevent internal resonance
and achieve optimal damping effects. In the nonlinear beam investigated in this study, the placement of a DVA between 0.25l and 0.5l from
the hinged end of the beam proved the most effective for damping; locations between 0.7l and 0.8l on the beam were ineffective. Finally,
numerical methods and simple experiments were studied to compare the results from MOMS and demonstrate the effects of the DVA of this
model.
Relation:
Journal of Engineering Mechanics 142(4), 04016003(25pages)