Commenced in January 2007
Paper Count: 31108
Simulation of Dynamic Behavior of Seismic Isolators Using a Parallel Elasto-Plastic Model
Abstract:In this paper, a one-dimensional (1d) Parallel Elasto- Plastic Model (PEPM), able to simulate the uniaxial dynamic behavior of seismic isolators having a continuously decreasing tangent stiffness with increasing displacement, is presented. The parallel modeling concept is applied to discretize the continuously decreasing tangent stiffness function, thus allowing to simulate the dynamic behavior of seismic isolation bearings by putting linear elastic and nonlinear elastic-perfectly plastic elements in parallel. The mathematical model has been validated by comparing the experimental force-displacement hysteresis loops, obtained testing a helical wire rope isolator and a recycled rubber-fiber reinforced bearing, with those predicted numerically. Good agreement between the simulated and experimental results shows that the proposed model can be an effective numerical tool to predict the forcedisplacement relationship of seismic isolators within relatively large displacements. Compared to the widely used Bouc-Wen model, the proposed one allows to avoid the numerical solution of a first order ordinary nonlinear differential equation for each time step of a nonlinear time history analysis, thus reducing the computation effort, and requires the evaluation of only three model parameters from experimental tests, namely the initial tangent stiffness, the asymptotic tangent stiffness, and a parameter defining the transition from the initial to the asymptotic tangent stiffness.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1128859Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 716
 J. M. Kelly, Earthquake-resistant Design with Rubber. London: Springer-Verlag, 1997.
 F. Naeim and J. M. Kelly, Design of Seismic Isolated Structures: From Theory to Practice. New York: John Wiley & Sons, 1999.
 M. C. Constantinou, A. S. Whittaker, Y. Kalpakidis, D. M. Fenz and G. P. Warn, “Performance of seismic isolation hardware under service and seismic loading,” Technical Report MCEER-07-0012, State University of New York, Buffalo, 2007.
 G. F. Demetriades, M. C. Constantinou and A. M. Reinhorn, “Study of wire rope systems for seismic protection of equipment in buildings,” Engineering Structures, vol. 15, no. 5, pp. 321-334, 1993.
 M. Spizzuoco, V. Quaglini, A. Calabrese, G. Serino and C. Zambrano, “Study of wire rope devices for improving the re-centering capability of base isolated buildings,” Structural Control and Health Monitoring, to be published.
 S. Nagarajaiah, A. M. Reinhorn and M. C. Constantinou, “Nonlinear dynamic analysis of 3-D base-isolated structures,” Journal of Structural Engineering, vol. 117, no. 7, pp. 2035-2054, 1991.
 A. Mroz, “Non-associated flow rules in plasticity,” Journal de Mecanique, vol. 2, pp. 21-42, 1963.
 D. R. J. Owen, A. Prakash and O. C. Zienkiewicz, “Finite element analysis of non-linear composite materials by use of overlay systems,” Computer and Structures, vol. 4, pp. 1251-1267, 1974.
 G. N. Pande, D. R. J. Owen and O. C. Zienkiewicz, “Overlay models in time-dependent nonlinear material analysis,” Computer and Structures, vol. 7, pp. 435-443, 1977.
 R. B. Nelson and A. Dorfmann, “Parallel elastoplastic models of inelastic material behavior,” Journal of Engineering Mechanics ASCE, vol. 121, no. 10, pp. 1089-1097, 1995.
 P. C. Tsopelas, P. C. Roussis, M. C. Constantinou, R. Buchanan and A. M. Reinhorn, “3D-BASIS-ME-MB: Computer program for nonlinear dynamic analysis of seismically isolated structures,” Technical Report MCEER-05-0009, State University of New York, Buffalo, 2005.
 S. Pagano, M. Russo, S. Strano and M. Terzo, “A mixed approach for the control of a testing equipment employed for earthquake isolation systems,” Journal of Mechanical Engineering Science, vol. 228, no. 2, pp. 246-261, 2014.
 M. Spizzuoco, A. Calabrese and G. Serino, “Innovative low-cost recycled rubber-fiber reinforced isolator: experimental tests and finite element analyses,” Engineering Structures, vol. 76, pp. 99-111, 2014.