TY - GEN
T1 - System identification to estimate the nonlinear modes of a gong
AU - Piombino, Daniel
AU - Allen, Matthew S.
AU - Ehrhardt, David
AU - Beberniss, Tim
AU - Hollkamp, Joseph J.
N1 - Funding Information:
Acknowledgements This work was supported by the Air Force Office of Scientific Research, Award # FA9550-17-1-0009, under the Multi-Scale Structural Mechanics and Prognosis program managed by Dr. Jaimie Tiley. The authors also wish to thank Mike Spottswood other collaborators in the Structural Sciences Center at the Air Force Research Laboratory for their support and for many helpful discussions.
Funding Information:
This work was supported by the Air Force Office of Scientific Research, Award # FA9550-17-1-0009, under the Multi-Scale Structural Mechanics and Prognosis program managed by Dr. Jaimie Tiley. The authors also wish to thank Mike Spottswood other collaborators in the Structural Sciences Center at the Air Force Research Laboratory for their support and for many helpful discussions.
Publisher Copyright:
© The Society for Experimental Mechanics, Inc. 2019.
PY - 2019
Y1 - 2019
N2 - Nonlinear Normal Modes (NNMs) have proven useful in a few recent works as a basis for comparing nonlinear models during model updating. In prior works the authors have used force appropriation to measure NNMs, but this is time consuming, generally requiring hand tuning of both the frequency in question and the strength of its harmonics. This paper explores the use of system identification, using a small set of broadband response data, to estimate a model from which the NNMs can be extracted. The Frequency Domain Restoring Force Surface (RFS) method will be used to perform identification, in which the nonlinearity of the system is assumed to be a polynomial function of the modal displacements, and a least squares problem is formed to solve for the nonlinear coefficients. Existing NNM calculation approaches can then be applied to the experimentally determined model in order to calculate the NNMs of the system. This approach is evaluated by applying it to full-field measurements from a traditional Gong, obtained using Stereo 3D Digital Image Correlation (3D– DIC). The results obtained using system identification are validated with measurements of the NNMs obtained using force appropriation and a scanning laser vibrometer.
AB - Nonlinear Normal Modes (NNMs) have proven useful in a few recent works as a basis for comparing nonlinear models during model updating. In prior works the authors have used force appropriation to measure NNMs, but this is time consuming, generally requiring hand tuning of both the frequency in question and the strength of its harmonics. This paper explores the use of system identification, using a small set of broadband response data, to estimate a model from which the NNMs can be extracted. The Frequency Domain Restoring Force Surface (RFS) method will be used to perform identification, in which the nonlinearity of the system is assumed to be a polynomial function of the modal displacements, and a least squares problem is formed to solve for the nonlinear coefficients. Existing NNM calculation approaches can then be applied to the experimentally determined model in order to calculate the NNMs of the system. This approach is evaluated by applying it to full-field measurements from a traditional Gong, obtained using Stereo 3D Digital Image Correlation (3D– DIC). The results obtained using system identification are validated with measurements of the NNMs obtained using force appropriation and a scanning laser vibrometer.
KW - Implicit condensation
KW - Model updating
KW - Reduced order modeling
KW - Vibration musical instrument
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U2 - 10.1007/978-3-319-74280-9_10
DO - 10.1007/978-3-319-74280-9_10
M3 - Conference contribution
AN - SCOPUS:85061137666
SN - 9783319742793
T3 - Conference Proceedings of the Society for Experimental Mechanics Series
SP - 121
EP - 136
BT - Nonlinear Dynamics - Proceedings of the 36th IMAC, A Conference and Exposition on Structural Dynamics 2018
A2 - Kerschen, Gaetan
PB - Springer
T2 - 36th IMAC, A Conference and Exposition on Structural Dynamics, 2018
Y2 - 12 February 2018 through 15 February 2018
ER -