Dynamics of vibration isolation system obeying fractional differentiation

Abstract

Purpose

The purpose of this paper is to analyze a new, whole‐spacecraft isolator and its performance of vibration isolation, which has been designed to ensure spacecraft safety at the launching stage.

Design/methodology/approach

The design is based on the analysis of fractional derivative stress‐strain constitutive relationship of viscoelastic materials. First, the authors study the constitutive relationships for viscoelastic solid of the damping materials, then the authors introduce the results obtained to the equations of motion for the damped isolator.

Findings

By performing a series of transformation, the authors obtain the analytical solution of the equations. It is shown that the results compare favourably to the numerical simulations and experiments. In addition, a saturation phenomenon for the first order damping ratio is also discussed.

Practical implications

It is found that the constitutive relationships written in terms of the fractional calculus can be applied in the system function of the whole‐spacecraft vibration isolator. Such relationships, developed previously from a model analysis base, have been shown to be useful tools for engineering analyses.

Originality/value

Some suggestions are given to improve the design of viscoelastic whole‐spacecraft isolators. The establishment of a theoretical basis for the new fractional differential dynamical system enhances their value, as they may now be used with increased reliability of satellite.

Citation

Li, S., Fang, B., Yang, T., Zhang, Y., Tan, L. and Huang, W. (2012), "Dynamics of vibration isolation system obeying fractional differentiation", Aircraft Engineering and Aerospace Technology, Vol. 84 No. 2, pp. 103-108. https://doi.org/10.1108/00022661211207910