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

Kohei Fujita,Izuru Takewaki

doi:10.3389/fbuil.2016.00029

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 shear-bending 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.

Highlights

The structural health monitoring has been studied and applied to many engineering fields, such as civil, mechanical, and aerospace structures, for the evaluation of the structural safety and the decision-making to operate the objective structures (Boller et al, 2009; Takewaki et al, 2011)
In the previous system identification (SI) method based on the identification function (IDF) as formulated in Eq 3, the limit manipulation of the IDF for ω → 0 was needed
(1) As an advanced stiffness identification method based on the shear-bending model (SB model), a new practical approach has been presented using both a shear model (S model) and a SB model to overcome the stability problem in the identification process in the previous SI method for the SB model

Summary

Introduction

The structural health monitoring has been studied and applied to many engineering fields, such as civil, mechanical, and aerospace structures, for the evaluation of the structural safety and the decision-making to operate the objective structures (Boller et al, 2009; Takewaki et al, 2011). It is well recognized that the modal-parameter SI and physical-parameter SI are two major branches in the field of SI. Much interest is focused on the modal-parameter SI, which can provide the overall mechanical properties of a structural system and has a stable characteristic. The physical-parameter SI is preferred in the structural health monitoring, its development is limited due to the requirement of multiple measurements or the necessity of complicated manipulation (Hart and Yao, 1977; Udwadia et al, 1978; Shinozuka and Ghanem, 1995; Takewaki and Nakamura, 2000, 2005; Brownjohn, 2003; Nagarajaiah and Basu, 2009; Takewaki et al, 2011; Zhang and Johnson, 2013)

Methods

Results

Discussion

Conclusion