Physics-Based Method for the Removal of Spurious Resonant Frequencies in High-Frequency Force Balance Tests
Publication: Journal of Structural Engineering
Volume 142, Issue 2
Abstract
The high-frequency force balance (HFFB) test is a widely used method for estimating lateral turbulent wind loads on tall buildings in a wind tunnel. The method relies on use of a highly accurate force sensor placed at the base of the tall building model to measure base forces and overturning moments. Because the turbulent wind load excitation is broadband, it is important to adequately design the connection detail between the model and the sensor. Accurate design is needed to avoid contaminating the measurement of the lateral wind loads by the potential spurious resonant effect, which is induced by flexibility in the connection detail. This design often relies on the experience of the wind tunnel modeler. On occasion, because of the limitations of test setup and environment, the connection detail between the building model and the HFFB force sensor may not be sufficiently stiff. Consequently, resonant response caused by the flexible connection may affect the power spectral density function of the measured wind loads. One of the methods to address this problem is to filter the HFFB output signal and to remove undesirable response within a specific frequency interval by conventional digital filter methods. However, this may cause the removal of important features of the wind loading. This paper presents a simple yet efficient method, based on classical dynamic theory, to eliminate the spurious effect. The method is applied to the “correction” of an experimental wind load spectrum.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
Mr. Kurt Braun, Department of Civil and Environmental Engineering of NEU, is gratefully acknowledged for fabrication of the wind tunnel setup and for assistance during experiments. Mr. Jonathan Doughty, Department of Mechanical and Industrial Engineering of NEU, is acknowledged for 3D printing and model fabrication. Messrs. David Abati and Darren Vokes of NEU’s Carpentry Department are gratefully acknowledged for the construction and assembly of the test chamber. Professor Jerome F. Hajjar and the Department of Civil and Environmental Engineering are gratefully acknowledged for their collaboration with the sensor equipment. Finally, the authors would like to thank the Department of Mechanical and Industrial Engineering of NEU for the shared use of wind tunnel facility. This paper is based on work supported by the National Science Foundation (NSF) of the United States under CAREER Award CMMI-0844977. Any opinions, findings and conclusions or recommendations are those of the authors and do not necessarily reflect the views of the NSF.
References
Bernardini, E., Spence, S. M., and Kareem, A. (2013). “A probabilistic approach for the full response estimation of tall buildings with 3d modes using the HFFB.” Struct. Saf., 44, 91–101.
Boggs, D., and Peterka, J. (1989). “Aerodynamic model tests of tall buildings.” J. Eng. Mech., 618–635.
Butterworth, S. (1930). “On the theory of filter amplifiers.” Exp. Wireless Wireless Eng., 7, 536–541.
Chen, X., and Kareem, A. (2005). “Validity of wind load distribution based on high frequency force balance measurements.” J. Struct. Eng., 984–987.
Cluni, F., Gusella, V., Spence, S., and Bartoli, G. (2011). “Wind action on regular and irregular tall buildings: Higher order moment statistical analysis by HFFB and SMPSS measurements.” J. Wind Eng. Ind. Aerodyn., 99(6–7), 682–690.
Davenport, A. G., and Tschanz, T. (1981). “The response of tall buildings to wind.” Proc., 4th U.S. National Conf. on Wind Engineering Research, National Science Foundation Wind Engineering Research Council and the Univ. of Washington, Seattle, Washington.
Holmes, J. D. (1987). “Mode shape corrections for dynamic response to wind.” Eng. Struct., 9(3), 210–212.
Kareem, A., and Cermak, J. (1978). “Wind tunnel simulation of wind-structure interactions.” Proc., 24th Int. Instrumentation Symp., ISA, Albuquerque, New Mexico.
Melbourne, W. (1980). “Comparison of measurements on the CAARC standard tall building model in simulated model wind flows.” J. Wind Eng. Ind. Aerodyn., 6(1), 73–88.
Reinhold, T. A., and Kareem, A. (1986). “Wind loads and building response predictions using force balance techniques.” Dynamic response of structures, G. C. Hart and R. B. Nelson, eds., ASCE, Reston, VA, 390–397.
Saunders, J., and Melbourne, W. (1975). “Tall rectangular building response to cross-wind excitation.” Proc., 4th Int. Conf. on Wind Effects on Buildings and Structures, Cambridge University Press, London, 369–380.
Stathopoulos, T., and Baniotopoulos, C. C. (2007). Wind effects on buildings and design of wind-sensitive structures, Springer, Vienna, Austria.
Steckley, A., Accardo, M., Gamble, S. L., and Irwin, P. A. (1992). “The use of integrated pressures to determine overall wind-induced response.” J. Wind Eng. Ind. Aerodyn., 42(1–3), 1023–1034.
Tschanz, T., and Davenport, A. (1983). “The base balance technique for the determination of dynamic wind loads.” J. Wind Eng. Ind. Aerodyn., 13(1–3), 429–439.
Tse, K., Hitchcock, P., and Kwok, K. (2009a). “Mode shape linearization for HFBB analysis of wind-excited complex tall buildings.” Eng. Struct., 31(3), 675–685.
Tse, K., Hitchcock, P., Kwok, K., Thepmongkorn, S., and Chan, C. (2009b). “Economic perspectives of aerodynamic treatments of square tall buildings.” J. Wind Eng. Ind. Aerodyn., 97(9–10), 455–467.
Zhou, Y., Kareem, A., and Gu, M. (2002). “Mode shape corrections for wind load effects.” J. Eng. Mech., 15–23.
Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 142 • Issue 2 • February 2016
Copyright
© 2015 American Society of Civil Engineers.
History
Received: Oct 18, 2014
Accepted: Aug 11, 2015
Published online: Sep 10, 2015
Published in print: Feb 1, 2016
Discussion open until: Feb 10, 2016
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.