Semi-active vibroisolation using elastomer electro-rheological and viscoelastic materials

Utilizing intelligent materials like: electro-rheological elastomer systems allows the design of vibroisolating dampers with possibility for variation of their characteristics (stiffness, frequency) with respect to the dynamic characteristics of the external force excitation. The objective of this paper is to show the possibility of modelling of vibroisolation mounts with variable characteristics utilizing electro-rheological and traditional elastomer materials. The mechanical and mathematical modelling is performed on the basis of a single degree of freedom (SDOF) model, considering shape and geometry factors. A forced response analysis is used to determine the resonant frequencies and amplitudes of the forced vibrations of viscoelastically damped structures. The analytically obtained results are validated by computer experiment. The frequency dependent properties of the Young’s modulus and loss factor are incorporated in the computer analysis in which a commercial code MATLAB is used. Natural frequencies and amplitudes of displacement are calculated by means of computer experiment in the single degree of freedom solution and correlated against the experimental test results. An attempt is made to control the dynamic system in two ways: control by changing the viscoelastic properties by variation of the electric current and by imposing motion restrictions on the forced response excitation. Numerical procedures have been developed and partially validated which provide a single degree of freedom analysis of the dynamic systems together with the modal characteristics. This enables future analysis to be carried out with confidence.