Nonlinear vibration analysis of a complex aerospace structure

S. B. Cooper*, D. Di Maio, D. J. Ewins

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademicpeer-review

1 Citation (Scopus)

Abstract

Complex shaped aerodynamic structures such missiles are prone to exhibit some level of nonlinear phenomena due to their aerodynamically tailored design and application. Aside from the aerodynamic and aeroelastic challenges experienced by a missile, an important but fundamental challenge encountered by a deployable missile is the inevitable concentrated structural nonlinearities which are observed around the hinge of its fins. Due to the current design and manufacturing process, the hinge of the fin of a missile often consist of complex configurations, joints and other nonlinear features that leads to concentrated structural nonlinearities. Some of the nonlinearities encountered includes off sets, piecewise linear, bilinear nonlinearity, hysteresis, coulomb friction and damping nonlinearities. These nonlinearities are frequently triggered at large vibration amplitudes caused by high pressure loads during operational flight. Activation of these nonlinearities often affect the dynamic response of the missile and in some cases lead to structural failures in the air vehicle. In this context, identifying and predicting the vibration response of aerodynamic structures with nonlinearities will be of great advantage to the present aerospace industries. In this paper the nonlinear dynamic behaviour of a prototype missile is examined using established nonlinear identification methods applied to measured data obtained from experimental test. The nonlinear identification is achieved using the acceleration surface method and the Hilbert transform FORCEVIB method, these methods are applied to sine-sweep excitation and stepped sine excitation measurements to obtain nonlinear parametric coefficients. The nonlinear experimental model was developed using the white box identification process (Detection, Characterisation and Parameter Estimation). In addition, Force controlled stepped sine experiments at several excitation levels were conducted to gain useful insight into the amplitude dependant behaviour of the missile in the existence of structural nonlinearities.

Original languageEnglish
Title of host publicationNonlinear Dynamics
Subtitle of host publicationProceedings of the 35th IMAC, A Conference and Exposition on Structural Dynamics 2017
EditorsGaetan Kerschen
Place of PublicationCham
PublisherSpringer
Pages55-68
Number of pages14
Volume1
ISBN (Electronic)978-3-319-54404-5
ISBN (Print)978-3-319-54403-8
DOIs
Publication statusPublished - 2017
Externally publishedYes
Event35th Conference and Exposition on Structural Dynamics, IMAC 2017 - Garden Grove, United States
Duration: 30 Jan 20172 Feb 2017
Conference number: 35

Publication series

NameConference Proceedings of the Society for Experimental Mechanics Series
PublisherSpringer
ISSN (Print)2191-5644
ISSN (Electronic)2191-5652

Conference

Conference35th Conference and Exposition on Structural Dynamics, IMAC 2017
Abbreviated titleIMAC
CountryUnited States
CityGarden Grove
Period30/01/172/02/17

Keywords

  • Experimental test
  • Missile
  • Structural nonlinearities and nonlinear identification

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