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...

The vibrations of elastic structures such as strings, beams, and plates can be described in terms of waves traveling in waveguides (Cremer et al., 1973; Graff, 1975; Fahy, 1987). While the subject of wave propagation has been extensively studied in the fields of acoustics in fluids and solids rather than vibrations of elastic structures, wave analysis techniques have been employed to reveal phy...

Free vibration of soil often occurs during earthquakes. Since the vibration caused by earthquake does not have (steady state harmonic vibration) continuity, the alluvium vibrates with its natural frequency between two natural seismic waves. This study evaluates the effect of piles on the period of free vibration of a soil layer using numerical method. In the first stage, using analytical equati...

This paper is concerned with the free and forced vibration responses of a magneto/electroactive dielectric elastomer, emphasizing chaotic phenomena. The elastomers under external magnetic electrical excitations undergo large elastic deformation. magnetodielectric elastomer modeled based on Gent–Gent strain energy function to incorporate influence second invariant stiffening. viscoelasticity act...

The ambient and forced vibration techniques for testing full-scale structures are critically compared. Both methods, based on small level excitation, may be used to determine many mode shapes and frequencies of vibration and the corresponding damping values, with adequate accuracy for most purposes. The two techniques give mutually consistent results. The mode amplitudes determined by ambient a...