Shear Strain Demands in Elastomeric Bearings Subjected to Rotation
Publication: Journal of Engineering Mechanics
Volume 143, Issue 4
Abstract
In seismic base isolation applications, fiber reinforcement was initially proposed as a potential cost-saving alternative to conventional steel reinforcement in laminated bearings. Steel reinforcement is often assumed to be rigid, but the extensibility of the reinforcement serves as an additional design parameter that must be considered. Similar to the compressibility of the elastomer, the extensibility of the reinforcement has a pronounced effect on important design parameters such as the compression modulus, bending modulus, and shear strains that develop because of compression or rotation. Analytical solutions for the bending modulus developed based on the pressure solution are available for most common pad geometries and can be used to derive the maximum shear strain due to rotation. These solutions are often complex and unsuitable for design purposes. In this study, the analytical solutions for an infinite strip, circular, square, rectangular, and annular pad geometries are derived and simplified to form geometry-specific approximations for the maximum shear strain due to rotation. The simplified approximations account for the reinforcement extensibility and the compressibility of the elastomer. The derived approximations are evaluated based on the analytical solutions and provide accurate values over a wide range of shape factors and values of bulk compressibility and reinforcement extensibility.
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Acknowledgments
Financial support for this study was provided by the McMaster University Centre for Effective Design of Structures (CEDS) funded through the Ontario Research and Development Challenge Fund (ORDCF) as well as an Early Researcher Award (ERA) grant. Both are programs of the Ministry of Research and Innovation (MRI). The support of the Natural Sciences and Engineering Research Council of Canada and a Vanier Canada Graduate Scholarship is gratefully acknowledged.
References
AASHTO. (2014a). “AASHTO LRFD bridge design specifications.” Washington, DC.
AASHTO. (2014b). “Guide specifications for seismic isolation design.” Washington, DC.
Al-Anany, Y. M., and Tait, M. J. (2015). “A numerical study on the compressive and rotational behavior of fiber reinforced elastomeric isolators (FREI).” Comp. Struct., 133, 1249–1266.
Angeli, P., Russo, G., and Paschini, A. (2013). “Carbon fiber-reinforced rectangular isolators with compressible elastomer: Analytical solution for compression and bending.” Int. J. Solids Struct., 50(22), 3519–3527.
Chalhoub, M. S., and Kelly, J. M. (1990). “Effect of bulk compressibility on the stiffness of cylindrical base isolation bearings.” Int. J. Solids Struct., 26(7), 743–760.
Chalhoub, M. S., and Kelly, J. M. (1991). “Analysis of infinite-strip-shaped base isolator with elastomer bulk compression.” J. Eng. Mech., 1791–1805.
Constantinou, M. C., Kalpakidis, I., Filiatrault, A., and Ecker Lay, R. A. (2011). “LRFD-based analysis and design procedures for bridge bearings and seismic isolators.”, Univ. at Buffalo, State Univ. of New York, Buffalo, NY.
CSA (Canadian Standards Association). (2014). “S6-14 Canadian highway bridge design code.” Mississauga, ON, Canada.
Das, A., Dutta, A., and Deb, S. K. (2015). “Performance of fiber-reinforced elastomeric base isolators under cyclic excitation.” Struct. Control Health, 22(2), 197–220.
De Raaf, M. G. P., Tait, M. J., and Toopchi-Nezhad, H. (2011). “Stability of fiber-reinforced elastomeric bearings in an unbonded application.” J. Compos. Mater., 45(18), 1873–1884.
Gent, A. N. (1964). “Elastic stability of rubber compression springs.” J. Mech. Eng. Sci., 6(4), 318–326.
Gent, A. N., and Lindley, P. B. (1959). “Compression of bonded rubber blocks.” Proc. Inst. Mech. Eng., 173(1), 111–122.
ISO. (2010). “Elastomeric seismic-protection isolators.” ISO 22762, Geneva.
Kelly, J. M. (1997). Earthquake-resistant design with rubber, Springer, London.
Kelly, J. M. (1999). “Analysis of fiber-reinforced elastomeric isolators.” J. Seismol. Earthquake Eng., 2(1), 19–34.
Kelly, J. M., and Konstantinidis, D. (2011). Mechanics of rubber bearings for seismic and vibration isolation, Wiley, Chichester, U.K.
Kelly, J. M., and Takhirov, S. M. (2002). “Analytical and experimental study of fiber-reinforced strip isolators.”, Pacific Earthquake Engineering Research Center, Univ. of California, Berkeley, CA.
Konstantinidis, D., Kelly, J. M, and Makris, N. (2008). “Experimental investigation on the seismic response of bridge bearings.”, Earthquake Engineering Research Center, Univ. of California, Berkeley, CA.
Nagarajaiah, S., and Ferrell, K. (1999). “Stability of elastomeric seismic isolation bearings.” J. Struct. Eng., 946–954.
Osgooei, P. M., Tait, M. J., and Konstantinidis, D. (2014a). “Three-dimensional finite element analysis of circular fiber-reinforced elastomeric bearings under compression.” Comp. Struct., 108, 191–204.
Osgooei, P. M., Van Engelen, N. C., Konstantinidis, D., and Tait, M. J. (2014b). “Experimental and finite element study on the lateral response of modified rectangular fiber-reinforced elastomeric isolators (MR-FREIs).” Eng. Struct., 85, 293–303.
Russo, G., Pauletta, M., and Cortesia, A. (2013). “A study on experimental shear behavior of fiber-reinforced elastomeric isolators with various fiber layouts, elastomers and aging conditions.” Eng. Struct., 52, 422–433.
Stanton, J. F., Roeder, C. W., Mackenzie-Helnwein, P., White, C., Kuester, C., and Craig, B. (2008). “Rotation limits for elastomeric bearings.”, Transportation Research Board, National Research Council, Washington, DC.
Stanton, J. F., Scroggins, G., Taylor, A. W., and Roeder, C. W. (1990). “Stability of laminated elastomeric bearings.” J. Eng. Mech., 1351–1371.
Toopchi-Nezhad, H., Tait, M. J., and Drysdale, R. G. (2008). “Testing and modeling of square carbon fiber-reinforced elastomeric seismic isolators.” Struct. Control Health, 15(6), 876–900.
Van Engelen, N. C., and Kelly, J. M. (2015). “Correcting for the influence of bulk compressibility on the design properties of elastomeric bearings.” J. Eng. Mech., .
Van Engelen, N. C., Konstantinidis, D., and Tait, M. J. (2016a). “Structural and nonstructural performance of a seismically isolated building using stable unbonded fiber‐reinforced elastomeric isolators.” Earthquake Eng. Struct. Dyn., 45(3), 421–439.
Van Engelen, N. C., Tait, M. J., and Konstantinidis, D. (2016b). “Development of code oriented formulas for elastomeric bearings including bulk compressibility and reinforcement extensibility.” J. Eng. Mech., .
Information & Authors
Information
Published In
Journal of Engineering Mechanics
Volume 143 • Issue 4 • April 2017
Copyright
©2017 American Society of Civil Engineers.
History
Received: Apr 25, 2016
Accepted: Sep 13, 2016
Published online: Jan 24, 2017
Published ahead of print: Jan 25, 2017
Published in print: Apr 1, 2017
Discussion open until: Jun 24, 2017
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