Share Email Print
cover

Proceedings Paper

Iterative constrained optimization scheme for model updating of long-span bridges
Author(s): Chih-Chen Chang; T. Y. P. Chang; Q. W. Zhang
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

This paper presents an iterative constrained optimization scheme for the finite element (FE) model updating of long-span bridges. The objective is to minimize the differences between the calculated and the measured frequencies by changing some selected structural parameters in the FE model. An eigenvalue sensitivity matrix is first obtained from the first-order Taylor series expansion of the eigenvalues with respect to these selected parameters. A set of linear equations relating the perturbation of parameters to the differences between the calculated and the measured frequencies is then established. The selected parameters are assumed to be bounded within some prescribed regions according to the degrees of uncertainty and variation existing in the parameters based on some engineering judgement. The changes of these parameters are found in an iterative fashion by solving a quadratic programming problem. This model updating scheme is applied to both a 1/150 scaled suspension bridge model in the laboratory and an actual cable- stayed bridge in the field. The results show that the natural frequencies calculated from the FE models after this updating process can be quite close to those of the measured values.

Paper Details

Date Published: 9 June 2000
PDF: 12 pages
Proc. SPIE 3995, Nondestructive Evaluation of Highways, Utilities, and Pipelines IV, (9 June 2000); doi: 10.1117/12.387825
Show Author Affiliations
Chih-Chen Chang, Hong Kong Univ. of Science and Technology (Hong Kong)
T. Y. P. Chang, Hong Kong Univ. of Science and Technology (Hong Kong)
Q. W. Zhang, Tongji Univ. (China)


Published in SPIE Proceedings Vol. 3995:
Nondestructive Evaluation of Highways, Utilities, and Pipelines IV
A. Emin Aktan; Stephen R. Gosselin; Stephen R. Gosselin, Editor(s)

© SPIE. Terms of Use
Back to Top