Low stiffness variation in structural systems: Identification and localization

Barone, Giorgio; Marino, F.; Pirrotta, Antonina

doi:10.1002/stc.246

Cited by 15 publications

(17 citation statements)

References 35 publications

(32 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…According to the above considerations, this indicates that the characteristics of analytical signal are ‘good features’ for low damage identification procedure. Moreover in 23 the same identification procedure was demonstrated to be valid also in the identification of entity and localization of multiple simultaneous damages.…”

Section: Introductionmentioning

confidence: 90%

“…The results of the damage identification procedure, developed in 22, are able to detect and localize 23 a damage even at an early stage.…”

Section: Damage Identification Proceduresmentioning

confidence: 99%

“…as well. But, in light of previous results 22–25, it seems that the best choice for η ( t ) is to use some characteristics of the analytical signal, having higher sensitivity to slight variation in system parameters.…”

Section: Damage Identification Proceduresmentioning

confidence: 99%

“…In 22 a damage identification procedure, proper for highlighting very low level of damage, has been performed. When dealing with a very low level of damage, for instance, a little variation in structural stiffness, this phenomenon cannot be detected either in time domain or in frequency domain, in fact in 23, it was stressed that the healthy impulse response function (IRF) and the healthy frequency response function (FRF) totally overlaps the IRF or the FRF of the damaged one; this indicates that both IRF and FRF are not ‘good features’ for low damage identification procedure. Then an identification procedure very useful to detect low variation of structural stiffness was developed.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

A damage identification procedure based on Hilbert transform: Experimental validation

Iacono¹,

Navarra²,

Pirrotta³

2010

Struct. Control Health Monit.

Self Cite

View full text Add to dashboard Cite

This paper aims at validating the feasibility of an identification procedure, based on the use of the Hilbert transform, by means of experimental tests for shear-type multi-degree-of-freedom systems. Particularly, a three-degree-of-freedom frame will be studied either numerically or experimentally by means of a laboratory scale model built at the laboratory of the Structural, Aerospace and Geotechnical Engineering Department (DISAG) of University of Palermo. Several damage scenarios have been considered to prove the effectiveness of the procedure. Moreover, the experimental tests have been conducted by considering two different input loads: pulse forces, simulated by means of an instrumental hammer, and wide band noise base inputs, by a shake table.In the first section the damage identification procedure, proposed in recent works, is presented. The procedure is based on the minimization of an objective function mathematically based on the properties of the analytical signal and the Hilbert transform. Second section reports the experimental model geometrical data and the data acquisition set-up as built in the DISAG laboratory. In Section 3, the results of the experimental campaigns are presented and discussed having considered three damage scenarios. The validated procedure has been proved to be able to not only detect damage even at early stage but it also needs processing of only few samples of the structural response.

show abstract

Section: Introductionmentioning

confidence: 90%

“…The results of the damage identification procedure, developed in 22, are able to detect and localize 23 a damage even at an early stage.…”

Section: Damage Identification Proceduresmentioning

confidence: 99%

Section: Damage Identification Proceduresmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A damage identification procedure based on Hilbert transform: Experimental validation

Iacono¹,

Navarra²,

Pirrotta³

2010

Struct. Control Health Monit.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Barone et al . 12 applied the phase of the structural response signal in damage detection in a structure with a low damage which results in a low stiffness variation. Frizzarin et al .…”

Section: Introductionmentioning

confidence: 99%

Glyco‐Scan: Varying Glycosylation in the Sequence of the Peptide Hormone PYY3‐36 and Its Effect on Receptor Selectivity

et al. 2010

View full text Add to dashboard Cite

The increasing prevalence of obesity worldwide calls for safe and highly efficacious satiety drugs. PYY3-36 has been implicated in food intake regulation, and novel peptide analogues with high Y2 receptor-subtype selectivity and potency have potential as drugs for the treatment of obesity. It has been hypothesized that PYY3-36 associates with the plasma membrane prior to receptor activation such that the amphipathic alpha-helix of PYY3-36 possibly guides the C-terminal pentapeptide into the correct conformation for receptor activation. Ala-scans are used routinely to study the effect of individual amino acids in a given peptide sequence. Here we report the glyco-scan of the peptide hormone PYY3-36, in which hydroxyl side-chain functionalities were glycosylated; in addition new glycosylation sites were introduced. An array of novel PYY3-36 analogues with a glycan positioned in the water-membrane interface or in the N terminal were screened for Y-receptor affinity and selectivity as well as metabolic stability. Interestingly, in contrast to the Y1 and Y4 receptors, the Y2 receptor readily accommodated glycosylations. Especially glycosylations in the alpha-helical region of PYY3-36 were favorable both in terms of Y-receptor selectivity and endopeptidase resistance. We thus report several PYY3-36 analogues with enhanced Y-receptor selectivity. Our results can be used in the design of novel PYY analogues for the treatment of obesity. The glyco-scan concept, as systematically demonstrated here, has the potential for a wider applicability.

show abstract

Crack detection in simply supported beams using stationary wavelet transform of modal data

Zhong

Oyadiji

2011

Struct. Control Health Monit.

View full text Add to dashboard Cite

A new approach, based on Stationary Wavelet Transform (SWT), is proposed in this paper for crack detection in beam-like structures. SWT is different from Discrete Wavelet Transform (DWT); SWT is a redundant transform that doubles the number of input samples at each iteration, which can provide a more accurate estimation of the variances and facilitate the identification of salient features in a signal, especially for recognizing noise or signal rupture.The mode shape of a cracked beam with a small crack depth, while apparently a single smooth curve, actually exhibits a local peak or discontinuity in the region of damage. The mode shape 'signal' can be approximately considered as that of the intact beam contaminated by 'noise' which consists of response noise and the additional response due to the crack. In this way, the signal can be decomposed by SWT into a smooth curve, called approximation coefficient, and a detail coefficient curve, which includes crack information that is useful for damage detection, respectively. In this paper, the modal responses of damaged simply supported beams are computed using the finite element method. The effect of noise on the proposed method is also studied. The numerical and experimental results demonstrate the efficiency of the proposed method for crack detection. It is shown that SWT of the modal data of cracked simply-supported beams provides a better crack indication than conventional DWT. The relationship between SWT detail coefficient and crack size (depth and width) are also discussed. A new method based 2 on the average difference of the SWT detail coefficient of vibration bending modes of a cracked beam and an intact beam is proposed as a damage index and verified.

show abstract

Low stiffness variation in structural systems: Identification and localization

Cited by 15 publications

References 35 publications

A damage identification procedure based on Hilbert transform: Experimental validation

A damage identification procedure based on Hilbert transform: Experimental validation

Glyco‐Scan: Varying Glycosylation in the Sequence of the Peptide Hormone PYY3‐36 and Its Effect on Receptor Selectivity

Crack detection in simply supported beams using stationary wavelet transform of modal data

Contact Info

Product

Resources

About