System Identification Approach to Detection of Structural Changes

Abstract. The identification problem of the existing structures though the Quasi-Newton and its modification, Trust region algorithms is discussed. For the structural problems, which could be represented by means of the mathematical modelling of the finite element code discussed method is extremely useful. The nonlinear minimization problem of the L 2 norm for the structures with linear elastic behaviour is solved by using of the Optimization Toolbox of Matlab. The direct and inverse procedures for the composition of the desired function to minimize are illustrated for the spatial 3D truss structure as well as for the problem of plane finite elements. The truss identification problem is solved with 2 and 3 unknown parameters in order to compare the computational efforts and for the graphical purposes. The particular commands of the Matlab codes are present in this paper.

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“…In order to obtain the values of unknown parameters we need to apply the minimization procedure [10,16].…”

Section: The Identification Problemmentioning

confidence: 99%

Structural Identification Problem

Suvorov

Palamá

Lysiakova

2016

MATEC Web of Conferences

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“…It is understood that the modal-parameter SI and the physical-parameter SI are two major branches in the field of SI. Great concern has been concentrated on the modalparameter SI (Hart and Yao, 1977;Agbabian et al, 1991;Shinozuka and Ghanem, 1995;Nagarajaiah and Basu, 2009;Takewaki and Nakamura, 2010), which can provide overall mechanical properties of a structural system and has a stable characteristic. For example, the subspace method is known as one of SI algorithms for the modal-parameter SI to identify input-state-output systems in terms of the parametrical system matrices (Van Overschee and De Moor, 1994;Peeters et al, 1997;Huang and Lin, 2001).…”

Section: Introductionmentioning

confidence: 99%

Modal–Physical Hybrid System Identification of High-rise Building via Subspace and Inverse-Mode Methods

Fujita

Fujimori

Takewaki

2017

Front. Built Environ.

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A system identification (SI) problem of high-rise buildings is investigated under restricted data environments. The shear and bending stiffnesses of a shear-bending model (SB model) representing the high-rise buildings are identified via the smart combination of the subspace and inverse-mode methods. Since the shear and bending stiffnesses of the SB model can be identified in the inverse-mode method by using the lowest mode of horizontal displacements and floor rotation angles, the lowest mode of the objective building is identified first by using the subspace method. Identification of the lowest mode is performed by using the amplitude of transfer functions derived in the subspace method. Considering the resolution in measuring the floor rotation angles in lower stories, floor rotation angles in most stories are predicted from the floor rotation angle at the top floor. An empirical equation of floor rotation angles is proposed by investigating those for various building models. From the viewpoint of application of the present SI method to practical situations, a non-simultaneous measurement system is also proposed. In order to investigate the reliability and accuracy of the proposed SI method, a 10-story building frame subjected to micro-tremor is examined.

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“…Originally, the modal SI as a popular technique was developed extensively. It can provide the overall mechanical properties of a structural system and has a stable characteristic (Hart and Yao, 1977, Agbabian et al, 1991, Nagarajaiah and Basu, 2009). On the other hand, the physical SI has another advantage that the stiffness and/or damping coefficients of the structural model can be recovered directly and is well suited to the design of passive control systems.…”

Section: Introductionmentioning

confidence: 99%

Frequency-Domain Physical-Parameter System Identification of Building Structures with Stiffness Eccentricity

Nabeshima

Takewaki

2017

Front. Built Environ.

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A frequency-domain method of physical-parameter system identification is developed for three-dimensional building structures with stiffness eccentricity. Equations of motion in the time domain are transformed into the frequency domain. The dynamic equilibrium of the free body above the j-th story is used to identify the j-th story stiffness and damping. It is required to measure the horizontal and rotational accelerations at all stories to identify the story stiffness and damping coefficients of all stories. Compared to the previous approach using the special identification function, the limit manipulation at zero frequency is unnecessary and is robust for noise. Furthermore, it should be remarked that the quantities of eccentricities in all stories can be identified using the slopes of the functions for torsional stiffness identification in the frequency domain.

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System Identification Approach to Detection of Structural Changes

Cited by 140 publications

References 12 publications

Structural Identification Problem

Structural Identification Problem

Modal–Physical Hybrid System Identification of High-rise Building via Subspace and Inverse-Mode Methods

Frequency-Domain Physical-Parameter System Identification of Building Structures with Stiffness Eccentricity

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