Mass–stiffness change method for scaling of operational mode shapes

Khatibi, Mohammad Mahdi; Ashory, M. R.; Malekjafarian, Abdollah; Brincker, Rune

doi:10.1016/j.ymssp.2011.07.012

Cited by 46 publications

(20 citation statements)

References 5 publications

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“…where is the th unitary-mass-normalized modal vector and is the normalization coefficient [30,31], generally different for each modal vector, obtained as…”

Section: Damage Detectionmentioning

confidence: 99%

“…The combination of the Reassigned WS-TSVD-based method (RWS-TSVD) for signal sparsification and the SVDbased approach for the computation of the flexibility matrix would allow fast recognizing structural damage by approximate calculations, without a large number of sensors and the knowledge of structural masses, only by using the acceleration time histories recorded at different points of the analyzed structure. In this way, contrary to other methods that provide specific tests to mass-normalize the modal matrix [30,31], it is possible to estimate the damage without interrupting the ordinary use of the analyzed structure. After a first quick test, the procedure could be reperformed by moving the sensors, in order to investigate more accurately the damage entity and location.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

On the Use of Singular Vectors for the Flexibility‐Based Damage Detection under the Assumption of Unknown Structural Masses

Quqa

Landi

Diotallevi

2018

Shock and Vibration

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The main purpose of this work is to investigate the usability of easily obtainable parameters instead of the modal traditional ones, in the context of a flexibility-based damage detection procedure, under the assumption of unknown structural masses. To this aim, a comparison is made between two different approaches: the first involves the calculation of the flexibility matrix by using traditional modal parameters, such as natural frequencies and modal vectors, normalized to unitary values, while the second involves the use of singular vectors, obtained through a simple matrix factorization. The modal parameters and the singular vectors necessary for the implementation of the damage detection procedure are evaluated through two different techniques: the Eigensystem Realization Algorithm and a wavelet-based procedure, for which a variant is proposed by introducing the energy reassignment concept into the original algorithm. Through the latter approach, in particular, it is possible to obtain a high number of singular vectors even in the case of reduced availability of sensors. The study is performed under the assumption of nonstationary excitation, in order to achieve general results, and the effectiveness of the procedures is evaluated through simulated tests regarding different structural schemes.

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“…where is the th unitary-mass-normalized modal vector and is the normalization coefficient [30,31], generally different for each modal vector, obtained as…”

Section: Damage Detectionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

On the Use of Singular Vectors for the Flexibility‐Based Damage Detection under the Assumption of Unknown Structural Masses

Quqa

Landi

Diotallevi

2018

Shock and Vibration

View full text Add to dashboard Cite

show abstract

“…Nevertheless, a minimal change is required in the magnitude of the mass [10,11] in order to ensure minimum frequency deviation and avoid uncertainties in the identification of modal analysis [12,13]. Moreover, the change of mass should not be too high in order to minimize the difference between the modified and unmodified modes of vibration.…”

Section: Introductionmentioning

confidence: 99%

Error analysis in obtaining scale factors with operational modal analysis and mass change

García¹

2015

Rev. Fac. Ing. Antioquia

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In operational modal analysis, the accuracy obtained in the identification of modal parameters, on the one hand, and the expertise in the modification of mass used to alter the dynamic behavior of the structure, on the other, decisively affect the accuracy achieved in the estimation of the scaling factors. Through experimental tests and numerical calculations, both the experimental validation of the estimate of the error in the scaling factor due to errors in the mode of vibration and the analysis of the influence of the modal mass in the variation of the scale factor, have been carried out. From all the above, it is concluded that it is necessary to pay special attention to how to make and modify inertial increments, i.e. changes in mass.----------Keywords: operational modal analysis, scaling factors, sensitivity, mass-change method ResumenEn el análisis modal operacional, por una parte, la exactitud obtenida en la identificación de los parámetros modales y, por otra, la pericia en la modificación de masa utilizada para alterar el comportamiento dinámico de la estructura, afectan de forma decisiva la exactitud alcanzada en la estimación de los factores de escala. Mediante ensayos experimentales y cálculo numérico, se ha realizado la validación experimental de la estimación del error en el factor de escala debido a errores en el modo de vibración, así como el análisis de la influencia de la masa modal en la variación del factor de escala. De 203Error analysis in obtaining scale factors with operational modal analysis and mass change todo ello se concluye que es necesario prestar especial atención a la forma de realizar y modificar los incrementos inerciales, es decir, la modificación de masa.----------Palabras clave: análisis modal operacional, factores de escala, sensibilidad, método del cambio de masa

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“…Contact based sensors such as accelerometers have been widely used for structural vibration tests (Farrar and James III 1997;Halling et al 2001;Khatibi et al 2012;Magalhães et al 2009). Contact based sensor system has three main components: sensor, Data Acquisition (DAQ) system and receiver.…”

Section: Contact Based Shm Sensor Systemmentioning

confidence: 99%

“…3.28 for obtaining scaled mode shape, { }. Khatibi et al (2012) suggested a way to scale mode shapes based on mass-stiffness change by the addition of mass and stiffness. The scheme of MScMS is shown in Figure 3.3.…”

Section: Stiffness-change Modal Scaling (Scms)mentioning

confidence: 99%

Non-contact based structural damage assessment using stochastic subspace identification and finite element model updating.

Yang¹

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Mass–stiffness change method for scaling of operational mode shapes

Cited by 46 publications

References 5 publications

On the Use of Singular Vectors for the Flexibility‐Based Damage Detection under the Assumption of Unknown Structural Masses

On the Use of Singular Vectors for the Flexibility‐Based Damage Detection under the Assumption of Unknown Structural Masses

Error analysis in obtaining scale factors with operational modal analysis and mass change

Non-contact based structural damage assessment using stochastic subspace identification and finite element model updating.

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