Piecewise nonlinear vibration isolator and design method therefor

Abstract

The invention discloses a piecewise nonlinear vibration isolator and a design method therefor. The method comprises: firstly, adopting an analytic method, i.e., an average method to obtain an amplitude frequency expression of vibration response of the piecewise nonlinear vibration isolator; secondly, according to the amplitude frequency expression, obtaining a relationship expression of an extreme response value and each parameter of a vibration system, adopting a numerical solution to obtain correct solutions and the number of solutions of the extreme response value, and obtaining a changing rule that the number of extreme response values changes with the parameters of the vibration system; thirdly, analyzing main structural parameters of the piecewise nonlinear vibration isolator, such as an influence of different measurement values of damping ratio and the value of base excitation on a frequency island and a changing rule of the number of the extreme response values, and if the number of the extreme response values is larger than 1, determining that the vibration response possibly causes a frequency island phenomenon, or otherwise, determining that the frequency island phenomenon does not occur; and finally, according to the values of the base excitation and the damping ratio, determining the structural parameters of the segmental nonlinear vibration isolator, so that the segmental nonlinear vibration isolator that avoids the frequency island phenomenon is designed. According to the method, the condition for removing frequency islands can be conveniently obtained; and the method is high in operability.

Description

technical field [0001] The invention belongs to the technical field of vibration isolation, and relates to a nonlinear vibration isolator with segmental stiffness characteristics, in particular to a segmental nonlinear vibration isolator and a design method thereof. Background technique [0002] Segmented stiffness vibration systems are ubiquitous in construction machinery, such as segmented nonlinear vibration isolators. The vibration response of this type of nonlinear vibration system may appear frequency island phenomenon under certain system parameters. Frequency islands refer to isolated closed curves above the main resonance response of a vibrating system. The generation of frequency island phenomenon will amplify the vibration response, which is not conducive to the isolation of vibration. Therefore, it is necessary to analyze the conditions for the occurrence of frequency island phenomenon and design a segmental nonlinear vibration isolator that avoids frequency isla...

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Problems solved by technology

[0004] The above analytical method is only suitable for simple piecewise linear vibration isolators, but for relatively complex piecewise nonlinear vibration isolators, it is difficult to obtain explicit analytical expressions for response extreme Conditions for Nonlinear Vibration Isolators to Eliminate Frequency Islands

However, the above numerical solution requires a large number of numerical calculations to obtain the response amplitude-frequency curve and can only obtain a stable solution, and its unstable solution cannot be obtained, so it is very time-consuming to obtain the conditions for eliminating the frequency island, so the operability is poor

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