Flexibility by Multireference Impact Testing for Bridge Diagnostics
Publication: Journal of Structural Engineering
Volume 118, Issue 8
Abstract
Modal testing by impact is a practical tool for structural identification, integrity monitoring, and diagnostics of bridges. Typically, nonlinearities in bridge response as well as sensitivity to ambient conditions are observed during modal tests. Therefore, impact tests should be planned and executed so that the effects of nonlinearities are incorporated in estimating modal parameters of a test structure. Furthermore, indexes more reliable than the modal parameters are needed to diagnose local and/or obscure damage. These and other shortcomings in current modal test‐based diagnostic studies are reviewed. A multireference impact testing of a bridge, in which frequency‐response functions (FRF) are measured and a large number of modal parameters are reliably identified, is presented. The mode shape coefficients obtained through processing measured FRF are directly transformed into flexibility of the test bridge without assuming mass. Analytical studies of a calibrated analytical model are presented to demonstrate that flexibility coefficients are more sensitive to local damage than either frequencies or mode shapes.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Aktan, A. E., Hogue, T. D., and Hoyos, A. (1988). “Regional identification of civil engineered structures.” Proc., Int. Workshop on Nondestructive Evaluation for Performance of Civil Structures, M. S. Agbabian and S. F. Masri, eds., U.S. National Science Foundation.
2.
Allemang, R. J., and Brown, D. L. (1987). “Experimental modal analysis and dynamic component synthesis.” Tech. Report AFWAL‐TR‐87‐3069, Univ. of Cincinnati, Cincinnati, Ohio.
3.
Bakht, B., and Jaeger, L. G. (1990). “Bridge testing—a surprise every time.” J. Struct. Engrg., ASCE, 116(5), 1370–1383.
4.
Biswas, M., Pandey, A. K., and Samman, M. M. (1989). “Diagnostic experimental spectral/modal analysis of a highway bridge.” Int. J. Anal. Experimental Modal Analysis, 5(1), 33–42.
5.
Chen, J.‐C, and Garba, J. A. (1988). “Structural damage assessment using system identification technique.” Proc., Structural Safety Evaluation based on System Identification Approaches, H. G. Natke and J. T. P. Yao, eds., Frieder Vieweg and Sohn, Germany.
6.
Douglas, B. M., and Reid, W. H. (1982). “Dynamic tests and system identification of bridges.” J. Struct. Div., ASCE, 108(10), 2295–2312.
7.
Ewins, D. J. (1984). Modal testing: Theory and practice. John Wiley and Sons Inc., New York, N.Y.
8.
GR 2515 computer‐aided test system operating manual. (1984). GenRad Inc., Santa Clara, Calif.
9.
Halvorsen, W. G., and Brown, D. L. (1977). “Impulse technique for structural frequency response testing.” Sound Vib., Nov., 8–21.
10.
Hogue, T. D., Aktan, A. E., and Hoyos, A. (1991). “Regional identification of constructed facilities.” J. Struct. Div., ASCE, 117(1), 128–148.
11.
Hoyos, A., and Aktan, A. E. (1987). “Regional identification of civil engineered structures based on impact induced transient responses.” Res. Report 87–1, Louisiana State Univ., Baton Rouge, La.
12.
Mazurek, D. F., and DeWolf, J. T. (1990). “Experimental study of bridge monitoring technique,” J. Struct. Engrg., ASCE, 116(9), 2532–2549.
13.
Natke, H. G., and Yao, J. T. P. (1987). “System identification approach in structural safety evaluation.” Proc., Workshop on Structural Safety Evaluation based on System Identification Approaches, H. G. Natke and J. T. P. Yao, eds., Frieder Vieweg and Sohn, Germany.
14.
Pinjarkar, S. G., Guedelhoefer, O. C., Smith, B. J., and Kritzler, R. W. (1990). Nondestructive load testing for bridge evaluation and rating. TRB, Nat. Res. Council, Washington, D.C.
15.
Raghavendrachar, M. (1991). “Global and regional structural identification of an RC bridge by impact testing,” Ph.D thesis, Univ. of Cincinnati, Cincinnati, Ohio.
16.
Richardson, J. A., and Douglas, B. M. (1987). “Identifying frequencies and three‐dimensional mode shapes from full scale bridge tests.” Proc., Fifth Int. Modal Analysis Conf.
17.
Rubin, S., and Coppolino, R. (1983). Flexibility monitoring evaluation study. Mineral Mgmt. Service, U.S. Dept. of Commerce, Washington, D.C.
18.
Salane, H. G., and Baldwin, J. W., Jr. (1990). “Identification of modal properties of bridges.” ASCE, 116(7), 2008–2021.
19.
Shih, C. Y., Tsuei, Y. G., Allemang, R. J., and Brown, D. L. (1989). “Complex mode indication function and its application to spatial domain parameter estimation.” Proc., Seventh Int. Modal Analysis Conf.
20.
Specifications for strength evaluation of existing steel and concrete bridges. (1989). American Association of Safety and Highway Transp. Officials (AASHTO), Washington, D.C.
21.
Modal‐Plus 9.0 reference manual. (1985). Struct. Dynamics Res. Corp., Milford, Ohio.
22.
Wilson, E. L., and Habibullah, A. (1988). “SAP90 user's manual.” Comput. Struct., Berkeley, Calif.
Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 118 • Issue 8 • August 1992
Pages: 2186 - 2203
Copyright
Copyright © 1992 ASCE.
History
Published online: Aug 1, 1992
Published in print: Aug 1992
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.