Advanced System Identification for High-Rise Building Using Shear-Bending Model

Abstract

In order to identify physical model parameters of a high-rise building, a new story stiffness identification method is presented based on a shear-bending model and the identification function. Although a shear building model may be the simplest conventional model for representing tall buildings, the system identification (SI) method using that model is not necessarily appropriate. This is because the influence of bending deformation is predominant in such high-rise buildings. For this reason, a shear-bending model is used where the shear and bending stiffnesses are unknown. In the previous researches using the shear-bending model, it was difficult to identify the bending stiffnesses stably and reliably. In this paper, to overcome such instability of bending stiffness identification of the shear-bending model, a new SI algorithm using both the shear model and the shearbending model is presented. The proposed SI algorithm is based on the observation that the fundamental-mode shape of the identified shear model is similar to that of the shear-bending model identified in the previous SI method. In order to verify the advanced SI method, two different 20-story building models are investigated in the numerical simulations. From the results of the simulations, both the shear and bending stiffnesses of the shear-bending model are identified reliably and stably in the proposed SI method.

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

“…The number of degrees of freedom in this SB model is 2 N, i.e., N for horizontal responses and N for rotational responses. In the previous researches on the SI method using the SB model (Minami et al, 2013;Fujita and Takewaki, 2016), only the horizontal accelerations observed in the numerical/experimental results were used to identify both shear and bending stiffnesses. Since the measurable data are limited in such identification, it is necessary to apply some optimization algorithms to minimize the error in the identification of modal parameters, i.e., natural frequencies.…”

“…By applying the ARX model to transfer functions, the difficulty in the evaluation of limit value for small SN-ratio data has been overcome (Fujita et al, 2015). On the other hand, the latter problem has been tackled by expanding the SI algorithm to the shear-bending model (SB model) (Fujita et al, 2013;Minami et al, 2013;Fujita and Takewaki, 2016). However, there exists an unstable phenomenon in identifying the bending stiffness due to the low sensitivity of bending stiffnesses on natural frequencies and/or responses.…”

Stiffness Identification of High-Rise Buildings Based on Statistical Model-Updating Approach

“…From the viewpoint of damage detection, this is quite effective. Although the physical parameter technique is preferred in the reliable development of SHM, its research advancement is limited because of the strict requirement on measurements (multiple measurement points) or the necessity of complex manipulation (Hart and Yao, 1977;Udwadia et al, 1978;Shinozuka and Ghanem, 1995;Nakamura, 2000, 2005;Brownjohn, 2003;Nagarajaiah and Basu, 2009;Takewaki et al, 2011;Zhang and Johnson, 2013a,b;Johnson and Wojtkiewicz, 2014;Wojtkiewicz and Johnson, 2014;Fujita and Takewaki, 2016;Song et al, 2017;Takewaki et al, 2017).…”