Vibration of two beams connected by nonlinear isolators: analytical and experimental study

Abstract

To study the coupling vibration of nonlinear isolators and flexible bodies, test rigs of two flexible beams connected by wire mesh isolators are constructed and investigated both experimentally and analytically. A five-parameter polynomial model of wire mesh isolators is derived by identifying parameters in the frequency domain with the sine-sweep test. For obtaining the parameters that are valid in a wide range of frequency, a numerically assisted identification method is developed. With this model, the vibration of two flexible beams connected by wire mesh isolators is studied. The frequency response is obtained analytically by employing the Green's function method and harmonic balance method. Sine-sweep test results with three test rigs show good coherence with the corresponding numerical results. With obtained experimental results and numerical results, effect of connection parameters is studied in detail. It is found that traditional design rules for isolators are no longer effective and the coupling vibration must be investigated in the design phase. Another phenomenon is that the damping has a function of weakening the effect of nonlinear stiffness. Nonlinear stiffness and nonlinear damping can decrease the transmissibility along with the increase of the excitation level.

Contribution to the Characterization of Vibration Isolators Based on Metal Mesh

“…References to this type of insulator can be found in the scientific literature under different names, such as "wire mesh", "metal mesh" and "metal rubber", because they show certain similarities to elastomeric insulators. Nonetheless, metal isolators have notable advantages [5] with respect to other types of isolators, such as high stiffness and amplitude of the hysteresis loop [6], great damping capacity [7], resistance to a large range of pressures and temperatures (−70 • C to 300 • C) [8] and high resistance to corrosion, among others. Furthermore, their stiffness and damping are less affected by temperature changes than other isolator types, they slightly degrade [9], and they are able to work in vacuum conditions and under radiation.…”

An exact dynamic stiffness method for multibody systems consisting of beams and rigid-bodies

“…Therefore, methods predominantly based on numerical techniques are not always suitable for modal analysis in the high frequency range [11] . To circumvent the above problem, many analytical models have been proposed for beam structures connected to various types of attachments such as lumped concentrated mass [12][13][14][15][16] and/or rotatory inertia [17] , spring and damper [18] , single spring-mass [14,[19][20][21][22][23][24][25][26] , double spring-mass [27][28][29][30][31][32] , spring-mass chain [33,34] which all have wide ranging applications in engineering. The attachment as lumped mass used in these publications is by and large assumed to be a concentrated point mass without any consideration to the size or dimension of the mass or its mass moment of inertia.…”

Dynamics of a Upright Pole Coupled with Nonlinear Hysteretic Isolators under Harmonic Base Excitation

“…The coefficients were identified by experimental data. Wang and Zheng [22] studied the coupling vibration of nonlinear isolators and two flexible beams by experimental and analytical methods. Shaska et al [23] explored the advantages and characteristics of nonlinear butyl rubber isolators in vibratory shear by comparison with linear isolators.…”