### Abstract

The focus of this investigation is on the formulation and validation of a methodology for the estimation of a stochastic linear modal model of a structure from measurements of a few of its natural frequencies and mode shapes on a few nominally identical samples of the structure. The basis for the modal model is composed of the modes of an approximate representation of the structure, e.g., a nonupdated or preliminary finite element model. Furthermore, the variability or uncertainty in the structure is assumed to originate from stiffness properties (e.g., Young's modulus, boundary conditions, attachment conditions) sothat the mass matrixof the uncertain linear modal model is identity but the corresponding stiffness matrix is random. The nonparametric stochastic modeling approach is adopted here for the representation of this latter matrix; thus, the quantities to be estimated are the mean stiffness matrix and the uncertainty level. This effort is accomplished using the maximum likelihood framework using both natural frequencies and mode shapes data. The successful application of this approach to data from the Air Force Institute of Technology joined wing is demonstrated. Copyright Clearance Center, Inc.

Original language | English (US) |
---|---|

Pages (from-to) | 870-884 |

Number of pages | 15 |

Journal | Journal of Aircraft |

Volume | 49 |

Issue number | 3 |

DOIs | |

State | Published - May 2012 |

### Fingerprint

### ASJC Scopus subject areas

- Aerospace Engineering

### Cite this

*Journal of Aircraft*,

*49*(3), 870-884. https://doi.org/10.2514/1.C031546

**Stochastic modeling of structural uncertainty/variability from ground vibration modal test data.** / Avalos, Javier; Swenson, Eric D.; Mignolet, Marc; Lindsley, Ned J.

Research output: Contribution to journal › Article

*Journal of Aircraft*, vol. 49, no. 3, pp. 870-884. https://doi.org/10.2514/1.C031546

}

TY - JOUR

T1 - Stochastic modeling of structural uncertainty/variability from ground vibration modal test data

AU - Avalos, Javier

AU - Swenson, Eric D.

AU - Mignolet, Marc

AU - Lindsley, Ned J.

PY - 2012/5

Y1 - 2012/5

N2 - The focus of this investigation is on the formulation and validation of a methodology for the estimation of a stochastic linear modal model of a structure from measurements of a few of its natural frequencies and mode shapes on a few nominally identical samples of the structure. The basis for the modal model is composed of the modes of an approximate representation of the structure, e.g., a nonupdated or preliminary finite element model. Furthermore, the variability or uncertainty in the structure is assumed to originate from stiffness properties (e.g., Young's modulus, boundary conditions, attachment conditions) sothat the mass matrixof the uncertain linear modal model is identity but the corresponding stiffness matrix is random. The nonparametric stochastic modeling approach is adopted here for the representation of this latter matrix; thus, the quantities to be estimated are the mean stiffness matrix and the uncertainty level. This effort is accomplished using the maximum likelihood framework using both natural frequencies and mode shapes data. The successful application of this approach to data from the Air Force Institute of Technology joined wing is demonstrated. Copyright Clearance Center, Inc.

AB - The focus of this investigation is on the formulation and validation of a methodology for the estimation of a stochastic linear modal model of a structure from measurements of a few of its natural frequencies and mode shapes on a few nominally identical samples of the structure. The basis for the modal model is composed of the modes of an approximate representation of the structure, e.g., a nonupdated or preliminary finite element model. Furthermore, the variability or uncertainty in the structure is assumed to originate from stiffness properties (e.g., Young's modulus, boundary conditions, attachment conditions) sothat the mass matrixof the uncertain linear modal model is identity but the corresponding stiffness matrix is random. The nonparametric stochastic modeling approach is adopted here for the representation of this latter matrix; thus, the quantities to be estimated are the mean stiffness matrix and the uncertainty level. This effort is accomplished using the maximum likelihood framework using both natural frequencies and mode shapes data. The successful application of this approach to data from the Air Force Institute of Technology joined wing is demonstrated. Copyright Clearance Center, Inc.

UR - http://www.scopus.com/inward/record.url?scp=84862606992&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84862606992&partnerID=8YFLogxK

U2 - 10.2514/1.C031546

DO - 10.2514/1.C031546

M3 - Article

AN - SCOPUS:84862606992

VL - 49

SP - 870

EP - 884

JO - Journal of Aircraft

JF - Journal of Aircraft

SN - 0021-8669

IS - 3

ER -