Full-field measurement of lightweight nonlinear structures using three-dimensional scanning laser Doppler vibrometry
File(s)
Accepted version
Author(s)
Wang, Xing
Yuan, Jie
Szydlowski, Michal
Schwingshackl, Christoph
Type
Journal Article
Abstract
Modern noncontact measurement techniques such as the three-dimensional scanning laser Doppler vibrometry (3D SLDV) are advantageous in measuring vibrations of lightweight, thin-walled aerospace structures, which were conventionally deemed as difficult or not feasible to apply using attached transducers. Nevertheless, the full-field measurements using 3D SLDV are still limited to extracting modal properties of linear structures, while measurements of complex nonlinear structures are rarely reported. This paper aims to extend the full-field measurement capability of 3D SLDV and combines it with a multiple-input–single-output vibration controller to deal with nonlinear structures. An advanced test strategy is introduced, which is capable of obtaining amplitude-dependent resonant frequencies, modal damping ratios, and full-field, multiharmonic mode shapes of nonlinear normal modes (NNMs). Conflicting parameters such as the frequency resolution and measurement time are optimized by combining phase separation and phase resonance testing techniques in a coherent strategy. The capabilities of the proposed nonlinear modal testing strategy are demonstrated on a realistic, large-scale fan blade that exhibits softening behaviors. Two of its NNMs were investigated at larger vibration amplitudes. Its nonlinear modal parameters were successfully extracted and validated, highlighting the time efficiency and data accuracy of the proposed strategy for measuring industrial-scale, lightweight nonlinear structures.
Date Issued
2025-04-01
Date Acceptance
2024-10-01
Citation
AIAA Journal: devoted to aerospace research and development, 2025, 63 (4), pp.1523-1540
ISSN
0001-1452
Publisher
American Institute of Aeronautics and Astronautics
Start Page
1523
End Page
1540
Journal / Book Title
AIAA Journal: devoted to aerospace research and development
Volume
63
Issue
4
Copyright Statement
Copyright © 2024 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved. This is the author’s accepted manuscript made available under a CC-BY licence in accordance with Imperial’s Research Publications Open Access policy (www.imperial.ac.uk/oa-policy)
License URL
Subjects
Aircraft Components and Structure
Communication Technology and Equipment
Dynamic Analysis
Engineering
Engineering, Aerospace
Finite Element Method
IDENTIFICATION
Mechanical and Structural Vibrations
Mechanical Testing
MODAL-ANALYSIS
Multiple Input Single Output
NORMAL-MODES
RESPONSES
Science & Technology
STRATEGY
SYSTEMS
Technology
Transducers
Turbomachinery
Vibration Measuring Instruments
Publication Status
Published
Date Publish Online
2024-10-30