in this paper, an analytical study of the forced vibrations of hexapod table is studied. considering external force as a time sinusoid force, forced vibrations of the platform are investigated. resonance frequencies and vibrations of the moving platform are also calculated in different directions. the results of the analytical approach are verified using fem simulation. modelling the harmonic m...

Elastic waves exhibit rich polarization characteristics absent in acoustic and electromagnetic waves. By designing a solid elastic metamaterial based on three-dimensional anisotropic locally resonant units, here we experimentally demonstrate polarization bandgaps together with exotic properties such as 'fluid-like' elasticity. We construct elastic rods with unusual vibrational properties, which...

The study describes a physical model of vibrating microtubules in living cells, presented as strings and bars. Calculated are proper-frequencies of first four vibration modes of transverse and longitudinal waves on microtubules. For microtubules with length 1-30μm and shear modulus 5.0×10 N/m the proper-frequencies of standing transverse waves fall in diapason of 1×10 5×10 Hz. For microtubules ...

Dynamic modulus of elasticity was determined in clearwood samples of eight tropical hardwood species using longitudinal vibrations, flexural vibration and ultrasonic transit-time methods. These samples were subsequently subjected to three point static bending test to determine static modulus of elasticity and modulus of rupture. Acoustic velocity and wood density were found to be independent pa...

This paper deals with a dynamical inverse problem for a composite beam formed by two connected beams. The vibrations of the composite beam are governed by a differential system where a coupling takes place between longitudinal and bending motions. In this paper, we neglect bending motions and we only deal with the longitudinal motions. These motions are governed by a two-by-two second order sys...