Identification of dynamic characteristics of nonlinear joint based on the optimum equivalent linear frequency response function

Kashani, Hamed Faghihi; Nobari, A.S.

doi:10.1016/j.jsv.2009.11.007

Cited by 20 publications

(25 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Using the same notation as in Section 3, the complex eigen-value problem for the FE model can be written as: (12) where and are the r-th eigen-value and eigen-vector of the model and is normalized such that (13) Differentiating Eq. (12) with respect to the updating variable gives (14) Pre-multiplying Eq. (14) by , rearranging the terms and using Eq.…”

Section: Formulation Of Iemmentioning

confidence: 99%

“…For a steel beam bonded to a heavy rigid steel block by a layer of adhesive, they measured the accelerance FRFs at different excitation levels, using the concept of Optimum Equivalent Linear FRF (OELF) [14] and identified the parameters of the nonlinear viscoelastic constitutive model. They validated the identified nonlinear viscoelastic model through correlation tests between the FRFs of the updated FE model and the experimental ones.…”

Section: Introduction *mentioning

confidence: 99%

See 1 more Smart Citation

Modification and evaluation of a FRF-based model updating method for identification of viscoelastic constitutive models for a nonlinear polyurethane adhesive in a bonded joint

Najib

Nobari

Nikbin

2017

International Journal of Adhesion and Adhesives

View full text Add to dashboard Cite

show abstract

Section: Formulation Of Iemmentioning

confidence: 99%

Section: Introduction *mentioning

confidence: 99%

Modification and evaluation of a FRF-based model updating method for identification of viscoelastic constitutive models for a nonlinear polyurethane adhesive in a bonded joint

Najib

Nobari

Nikbin

2017

International Journal of Adhesion and Adhesives

View full text Add to dashboard Cite

show abstract

“…As the experimental efficiency of the identification technique has not been examined in [8], it is the aim of this paper to examine this efficiency. To this end, an experimental model of a vibrating system including a nonlinear joint is considered.…”

Section: Case Studymentioning

confidence: 99%

“…The applied identification method is a frequency domain method, one which is developed by Kashani and Nobari [8]. The identification process uses a FE model updating method to find the parameters that are the sources of differences between optimum equivalent linear FRF of the nonlinear system (OELF) and the linear FRFs derived from FEM.…”

Section: Introductionmentioning

confidence: 99%

Identification of a nonlinear joint in an elastic structure using optimum equivalent linear frequency response function

2012

View full text Add to dashboard Cite

As the main source of local nonlinearities, joints can lead to drastic changes in dynamic behavior of structures in a global scale. Finite element (FE) models often lack these nonlinearities and are incapable of representing nonlinear behavior. Therefore, the identification of nonlinear dynamic mechanical properties of the joint is necessary, in order to develop a faithful FE model of the structure. In the present work, dynamic parameters of a nonlinear joint are identified using an optimum equivalent linear frequency response function of the structure. A test rig, which includes a beam that can produce cubic stiffness spring characteristic as a nonlinear joint, is built, and nonlinear dynamic characteristics of the beam are identified. In addition to hardening behavior related to cubic stiffness, softening effects were also observed in some measured modes in which further investigation attributed that behavior to the presence of a bolt in the test rig.

show abstract

“…For transforming equations to the frequency domain, FRF coupling method is extended to nonlinear aeroelasticity by utilizing the concept of OELF. The OELF concept has been used and developed for identification process by Kashani et al [11].…”

Section: Introductionmentioning

confidence: 99%

Nonlinear aeroelastic stability analysis of hingeless helicopter rotor blades using FRF coupling and condition number

2015

View full text Add to dashboard Cite

In this paper, aeroelastic stability analysis of hingeless helicopter blades in frequency domain is studied. In this regard, the nonlinear structural beam model of Hodges-Dowell and an unsteady aerodynamic model based on Greenberg theory and using Loewy aerodynamic function are considered to construct the aeroelastic model. Then, the concept of optimum equivalent linear frequency response function (OELF) is implemented to derive the aeroelastic FRF by coupling the aerodynamic and structural FRFs. Finally, for stability analysis, the efficient and simple criterion of condition number (CN) of aeroelastic OELF is applied. The comparison of the obtained results against those in the literature shows the capability of the OELF and condition number criterion for capturing the instability boundaries of a complex, nonlinear, aeroelastic system such as helicopter blades.

show abstract

Identification of dynamic characteristics of nonlinear joint based on the optimum equivalent linear frequency response function

Cited by 20 publications

References 20 publications

Modification and evaluation of a FRF-based model updating method for identification of viscoelastic constitutive models for a nonlinear polyurethane adhesive in a bonded joint

Modification and evaluation of a FRF-based model updating method for identification of viscoelastic constitutive models for a nonlinear polyurethane adhesive in a bonded joint

Identification of a nonlinear joint in an elastic structure using optimum equivalent linear frequency response function

Nonlinear aeroelastic stability analysis of hingeless helicopter rotor blades using FRF coupling and condition number

Contact Info

Product

Resources

About