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Time (sec)
Time (sec)
Time (sec)
Fie.3.5 Input ground acceleration Fig.3.6. Estimated ground motion Fig.3.7 Estimated ground motion
motion for 5% noise level in NC1 for 3% noise level in NC2
CONCLUSIONS
The dynamic compound inverse method has been introduced in this paper for simultaneously
identifying the structural parameters and the ground motion using the measured structural .responses
only. Numerical examples using a three-story shear building showed that the method could accurately
identify the structural parameters and the ground motion simultaneously when the dynamic responses
were noise free. For the dynamic responses at the same building floor polluted by the same noise
process, the compound inverse method could still accurately identity the building stiffness coefficients
but the damping coefficients and the peak acceleration of the ground motion were estimated with some
acceptable errors. If the dynamic responses at the same building floor polluted by different noise
processes, the maximum identification errors increase moderately for damping coefficients and input
peak acceleration but considerably for stiffness coefficients when compared with the case with the
same noise process concerned. The extension and the further application of the method are under way.
ACKNOWLEDGEMENTS
The writers are grateful for the financial support from Tongji University through a PhD studentship to
the first writer and The Hong Kong Polytechnic University through Young Professor Scheme to the
third writer.
REFERENCES
Cho H. N. and Paik S. W (2000), Time domain system identification technique with unknown input
and limited observation, Proceedings of 8 th ASCE specially conference on Probabilistic Mechanics
and Structural Reliability, PMC2000-190
dough R.W. and Penzien J. (1993), " Dynamics of Structures", 2nd Edition, McGraw-Hill, Inc.
Hoshiya M. and Sutoh A. (1995), Identification of input and parameters of a MDOF system,
Proceedings ofEASEC-5, Gold Coast, Australia, 1309-1314
Hsia T. C. (1977), System identification: least-squares methods, Lexington, Mass
Toki K., Sato T. and Kiyono J. (1989), Identification of structural parameters and input ground motion
from response time histories, Structural Eng./Earthquake Eng, 6:2, 413-421
Wang D. and Haldar A. (1994), Element-level system identification with unknown input, J. of
Engineering Mechanics, ASCE, 120:1, 159-175
Wang D. and Haldar A. (1997), System idetification with limited observation and without input, J of
Engineering Mechanics, ASCE, 123:5, 504-511
Yang J. N. and Agrawal A. K. (2000), Protective system for high-technology facilities against
microvibration and earthquake, J. of Structural Engineering and Mechanics, 10:6, 561-575