Time-Domain Model for Predicting Aerodynamic Loads on a Slender Support Structure for Fatigue Design
Publication: Journal of Engineering Mechanics
Volume 136, Issue 6
Abstract
This paper presents the development of a universal model for predicting cyclic aerodynamic loads originating from buffeting, self-excited, and vortex shedding on a slender support structure in the time domain that can be used to predict its fatigue life. To accomplish this development, long-term monitoring was performed on a high mast light pole (HMLP) and the field data were used to validate the developed mathematical model. Wind-tunnel tests were conducted on the dodecagonal (12-sided) cylindrical cross section of the light pole to obtain the necessary aerodynamic parameters such as static force coefficients, Strouhal number, and indicial functions for buffeting that appear in the postulated model. Furthermore, these aerodynamic parameters were cast into a coupled dynamic model for predicting the response of any HMLP in time domain from vortex shedding and buffeting.
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Acknowledgments
The writers acknowledge the usage of the Bill James Wind Tunnel in the Wind Simulation and Testing Laboratory (WiST Lab) and thank the staff of the WiST Lab and the Bridge Engineering Center at Iowa State University for their support of the experimental work. The writers are thankful to the Iowa Department of Transportation and Midwest Transportation Consortium for sponsoring this work.
References
AASHTO. (2001). Standard specifications for structural supports for highway signs, luminaires, and traffic signals, 4th Ed., AASHTO, Washington, D.C.
Caracoglia, L., and Jones, N. P. (2003). “Time domain vs. frequency domain characterization of aeroelastic forces for bridge deck sections.” J. Wind. Eng. Ind. Aerodyn., 91, 371–402.
Chen, X., and Kareem, A. (2000). “Time domain flutter and buffeting response analysis of bridges.” J. Eng. Mech., 126(1), 7–16.
Chen, X., and Kareem, A. (2002). “Advances in modeling of aerodynamic forces on bridge decks.” J. Eng. Mech., 128(11), 1193–1205.
Chowdhury, A. G., and Sarkar, P. P. (2004). “A novel elastic suspension system for wind tunnel section model studies.” Wind Struct., 92(1), 23–24.
Connor, R. J., and Hodgson, I. C. (2006). “Field instrumentation and testing of high-mast lighting towers in the State of Iowa.” Final Rep. Prepared for Iowa Dept. of Transportation, Ames, Iowa.
Costa, C. (2007). “Aerodynamic admittance functions and buffeting forces for bridges via indicial functions.” J. Fluids Struct., 23, 413–428.
Costa, C., and Borri, C. (2006). “Application of indicial functions in bridge deck aeroelasticity.” J. Wind Eng. Ind. Aerodyn., 94, 859–881.
Gupta, H., and Sarkar, P. P. (1996). “Identification of vortex-induced response parameters in time domain.” J. Eng. Mech., 122(11), 1031–1037.
James, W. D. (1976). “Effects of Reynolds number and corner radius on two-dimensional flow around octagonal, dodecagonal and hexdecagonal cylinder.” Ph.D. dissertation, Iowa State Univ., Ames, Iowa.
Jancauskas, E. D. (1983). “The cross-wind excitation of bluff structures and the incident turbulence mechanism.” Ph.D. dissertation, Monash Univ., Melbourne, Australia.
Jancauskas, E. D., and Melbourne, W. H. (1986). “The aerodynamic admittance of two-dimensional rectangular section cylinders in smooth flow.” J. Wind Eng. Ind. Aerodyn., 23, 395–408.
Liepmann, H. W. (1952). “On the application of statistical concepts to the buffeting problem.” J. Aeronaut. Sci., 19, 793–800.
Peil, U., and Behrens, M. (2002). “Fatigue of tubular steel lighting columns under wind load.” Wind Struct., 5(5), 463–478.
Repetto, M. P., and Solari, G. (2004). “Directional wind-induced fatigue of slender vertical structures.” J. Struct. Eng., 130(7), 1032–1040.
Scanlan, R. H. (1984). “Role of indicial functions in buffeting analysis of bridges.” J. Struct. Eng., 110(7), 1433–1446.
Scanlan, R. H. (1993). “Problematics in formulation of wind-force models for bridge decks.” J. Eng. Mech., 119(7), 1353–1375.
Scruton, C. (1981). “An introduction to wind effects on structures.” Engineering design guides 40, BSI&CEI, Oxford, U.K.
Sears, W. R. (1941). “Some aspects of non-stationary airfoil theory and its practical applications.” J. Aeronaut. Sci., 8, 104–108.
Shinozuka, M. (1971). “Simulation of multivariate and multidimensional random processes.” J. Acoust. Soc. Am., 49, 357–368.
Simiu, E., and Scanlan, R. H. (1996). Wind effects on structures, fundamentals and applications to design, 3rd Ed., Wiley, New York.
Skop, R. A., and Griffin, O. M. (1975). “On a theory for the vortex-excited oscillations of flexible cylindrical structures.” J. Sound Vib., 41, 263–274.
Vickery, B. J. (1965). “On the flow behind a coarse grid and its use as a model of atmospheric turbulence in studies related to wind loads on buildings.” National Physical Laboratory Aero Rep. No. 1143.
Zhang, X., and Brownjohn, J. M. W. (2003). “Time domain formulation of self-excited forces on bridge deck for wind tunnel experiment.” J. Wind Eng. Ind. Aerodyn., 91, 723–736.
Information & Authors
Information
Published In
Journal of Engineering Mechanics
Volume 136 • Issue 6 • June 2010
Pages: 736 - 746
Copyright
© 2010 ASCE.
History
Received: Nov 19, 2008
Accepted: Nov 19, 2009
Published online: Nov 21, 2009
Published in print: Jun 2010
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