Parameter identification of torsionally coupled shear buildings from earthquake response records

This paper presents an efficient procedure to determine the natural frequencies, modal damping ratios and mode shapes for torsionally coupled shear buildings using earthquake response records. It is shown that the responses recorded at the top and first floor levels are sufficient to identify the dominant modal properties of a multistoried torsionally coupled shear building with uniform mass and constant eccentricity even when the input excitation is not known. The procedure applies eigenrealization algorithm to generate the state-space model of the structure using the cross-correlations among the measured responses. The dynamic characteristics of the structure are determined from the state-space realization matrices. Since the mode shapes are obtained only at the instrumented floor (top and first floors) levels, a new mode shape interpolation technique has been proposed to estimate the mode shape coefficients at the remaining floor levels. The application of the procedure has been demonstrated through a numerical experiment on an eight-storied torsionally coupled shear building subjected to earthquake base excitation. The results show that the proposed parameter identification technique is capable of identifying dominant modal parameters and responses even with significant noise contamination of the response records. Copyright © 2008 John Wiley & Sons, Ltd.

[1]  U. Kadakal,et al.  A comparative study on the identification methods for the autoregressive modelling from the ambient vibration records , 1996 .

[2]  Chi-Chang Lin,et al.  System identification of torsionally coupled buildings , 2000 .

[3]  H. G. Natke,et al.  System identification techniques , 1986 .

[4]  Snehashish Chakraverty.  Identification of structural parameters of multistorey shear buildings from modal data , 2005 .

[5]  Erik A. Johnson,et al.  NATURAL EXCITATION TECHNIQUE AND EIGENSYSTEM REALIZATION ALGORITHM FOR PHASE I OF THE IASC-ASCE BENCHMARK PROBLEM: SIMULATED DATA , 2004 .

[6]  Richard Kronland-Martinet,et al.  IDENTIFICATION OF COUPLED NON-LINEAR MODES FROM FREE VIBRATION USING TIME-FREQUENCY REPRESENTATIONS , 2001 .

[7]  F. Shen,et al.  USING THE CROSS-CORRELATION TECHNIQUE TO EXTRACT MODAL PARAMETERS ON RESPONSE-ONLY DATA , 2003 .

[8]  Thomas G. Carne,et al.  The Natural Excitation Technique (NExT) for modal parameter extraction from operating wind turbines , 1993 .

[9]  Tadanobu Sato,et al.  IDENTIFICATION OF STRUCTURAL PARAMETERS AND INPUT GROUND MOTION FROM RESPONSE TIME HISTORIES , 1989 .

[10]  Xingrui Ma,et al.  Estimated mass and stiffness matrices of shear building from modal test data , 1998 .

[11]  Henry J. Rice,et al.  A procedure for the identification of linear and non-linear multi-degree-of-freedom systems , 1991 .

[12]  P. Welch.  The use of fast Fourier transform for the estimation of power spectra: A method based on time averaging over short, modified periodograms , 1967 .

[13]  Achintya Haldar,et al.  Element-level system identification with unknown input , 1994 .

[14]  Mehmet Çelebi,et al.  Closure of "Method to Estimate Center of Rigidity Using Vibration Recordings" , 1990 .

[15]  M. Çelebi,et al.  TORSIONAL RESPONSE OF UNIQUE BUILDING , 1991 .

[16]  S. T. Mau,et al.  Story-Drift, Shear, and OTM Estimation from Building Seismic Records , 1994 .

[17]  C. Farrar,et al.  SYSTEM IDENTIFICATION FROM AMBIENT VIBRATION MEASUREMENTS ON A BRIDGE , 1997 .

[18]  Jer-Nan Juang,et al.  An eigensystem realization algorithm for modal parameter identification and model reduction. [control systems design for large space structures] , 1985 .

[19]  Randall J. Allemang,et al.  THE MODAL ASSURANCE CRITERION–TWENTY YEARS OF USE AND ABUSE , 2003 .

[20]  Anil K. Chopra,et al.  Elastic Earthquake Analysis of a Class of Torsionally Coupled Buildings , 1977 .

[21]  Ming-Shaung Ju,et al.  EXTRACTION OF NORMAL MODES FOR HIGHLY COUPLED INCOMPLETE SYSTEMS WITH GENERAL DAMPING , 1996 .