Identification of linear structural systems using earthquake-induced vibration data

Abstract

This paper addresses the issue of system identi"cation for linear structural systems using earthquake induced time histories of the structural response. The proposed methodology is based on the Eigensystem Realization Algorithm (ERA) and on the Observer/Kalman "lter IDenti"cation (OKID) approach to perform identi"cation of structural systems using general input}output data via Markov parameters. The e$ciency of the proposed technique is shown by numerical examples for the case of eight-storey building "nite element models subjected to earthquake excitation and by the analysis of the data from the dynamic response of the Vincent-Thomas cable suspension bridge (Long Beach, CA) recorded during the Whittier and the Northridge earthquakes. The e!ects of noise in the measurements and of inadequate instrumentation are investigated. It is shown that the identi"ed models show excellent agreement with the real systems in predicting the structural response time histories when subjected to earthquake-induced ground motion.

Vibration Analysis and Models of Adjacent Structures Controlled by Magnetorheological Dampers

“…The ERA/OKID algorithm [24,25,29] is utilized to provide an identified first-order representation of the system. The measured bidirectional base acceleration ( = , ) and the structural responses provide data to obtain, after a certain number of calculations, the first-order representation that may be rewritten also in a modal representation.…”

“…The campaign is carried out on a shaking table using a wide variety of base excitations such as sine sweep, white noise, and natural earthquakes, at several intensities. The method for the identification procedure and model definition follows three steps: (i) the vibration analysis of the system, (ii) the identification of first-order modal models from experimental data through the ERA/OKID algorithm [24,25], and (iii) the definition of an accurate finite element model by means of an updating procedure. The procedure is applied at a first stage in the original nonconnected configuration, which represents a linear system, and then in the connected configuration, which represents a nonlinear system due to the presence of the MR damper.…”

Health Diagnostics of Highway Bridges Using Vibration Response Data

“…The method presents a unified procedure to build state-space models of linear time-invariant systems from the measured data. Applications of the method to civil engineering structures are reported in (Luş, et al 1999;Luş, et al 2002, andUlusoy, et al 2011.). In this procedure, a finite dimensional, linear, time-invariant system is described by:…”

Simultaneous identification of structural parameters and dynamic input with incomplete output-only measurements

“…In contrast, TDMs aim to estimate the system's physical parameters using directly the time histories of the observed structural response and trying to create a mathematical (physical or non‐physical) model that simulates such response as closely as possible. Among the TDMs, it is noteworthy to list the identification approaches based on least‐squares methods , the Kalman filters , the particle filter , the H ∞ filter and the sequential Monte Carlo method . These methods have proven to be successful in application to structural parametric identification.…”