Nonlinear and chaotic behavior of structural system investigated by wavelet transform techniques

Structural pounding can cause considerable damage and even lead to collapse of structures. Most research focuses on modeling, parameter investigation, and mitigation approaches. With the development of structural health monitoring, the on-line detection of pounding becomes possible. The detection of pounding can provide useful information of potential damage of structures. This paper proposed using wavelet scalograms of dynamic response to detect pounding and examined the feasibility of this method. Numerical investigations were performed on a pounding system that consisted of a damped single-degree-of-freedom (SDOF) structure and a rigid barrier. Hertz contact model was used to simulate pounding behavior. The responses and pounding forces of the system under harmonic and earthquake excitations were numerically solved. The wavelet scalograms of acceleration responses were used to identify poundings. It was found that the scalograms can indicate the occurrence of pounding and occurrence time very well. The severity of the poundings was also approximately estimated. Experimental studies were carried out, in which shake table tests were conducted on a bridge model that underwent pounding between its different components during ground motion excitation. The wavelet scalograms of the bridge responses indicated pounding occurrence quite well. Hence the conclusions from the numerical studies were verified experimentally.

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“…The modulus and phase were used in [17] to investigate nonlinear and chaotic behavior of structural systems.…”

Section: Wavelet Transform and Scalogrammentioning

confidence: 99%

Structural Pounding Detection by Using Wavelet Scalogram

Xing

Halling

Meng

2012

Advances in Acoustics and Vibration

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“…In this paper, the WT has been demonstrated by choosing the following standard complex Morlet mother wavelet (11) where defines the center frequency of the wavelet.…”

Section: Wavelet Analysismentioning

confidence: 99%

Determination of wavelet ridges of nonstationary signals by singular value decomposition

Özkurt

Savacı

2005

IEEE Trans. Circuits Syst. II

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Abstract-The ridges obtained from chaotic signals can give the relevant information about the phase structures of the dynamical systems. Therefore, a new wavelet ridge determination method for the noisy signals and nonstationary signals, which is based on the singular value decomposition (SVD) has been proposed in this paper. The proposed method has been compared with Carmona method for monocomponent signals, and multicomponent signals. The proposed method is computationally more effective than the Carmona method to determine the actual ridges. Also, the ridges of the periodic limit cycles and chaotic attractors have been determined by using the SVD-based method to find the degree of chaoticity.Index Terms-Instantaneous frequency, singular value decomposition (SVD), wavelet ridge.

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“…Furthermore, there are no certain procedures especially for the synthesis of nonlinear circuits, instead there are specific solutions for several applications. Since the time-domain methods and frequency-domain methods alone do not provide adequate information about the dynamics of such signals, there have been several studies on the analysis of the nonlinear dynamical systems with time-frequency domain methods [1][2][3][4][5][6]. Also, there have been studies on the reconstruction of the attractors of the chaotic systems using the Wigner-Ville distribution [7] and the wavelet transform [8].…”

Section: Introductionmentioning

confidence: 99%