ENERGY BALANCE-BASED SEISMIC RESPONSE PREDICTION METHODS FOR SEISMIC ISOLATED BUILDINGS WITH RUBBER BEARINGS, DAMPERS AND LOW FRICTION ELASTIC SLIDING BEARINGS

AbstractNumerical methods for the solution of dynamical problems in engineering go back to 1950. The most famous and widely-used time stepping algorithm was developed by Newmark in 1959. In the present study, for the first time, the Newmark algorithm is developed for the case of the trilinear hysteretic model, a model that was used to describe the shear behaviour of high damping rubber bearings. This model is calibrated against free-vibration field tests implemented on a hybrid base isolated building, namely the Solarino project in Italy, as well as against laboratory experiments. A single-degree-of-freedom system is used to describe the behaviour of a low-rise building isolated with a hybrid system comprising high damping rubber bearings and low friction sliding bearings. The behaviour of the high damping rubber bearings is simulated by the trilinear hysteretic model, while the description of the behaviour of the low friction sliding bearings is modeled by a linear Coulomb friction model. In order to prove the effectiveness of the numerical method we compare the analytically solved trilinear hysteretic model calibrated from free-vibration field tests (Solarino project) against the same model solved with the Newmark method with Netwon-Raphson iteration. Almost perfect agreement is observed between the semi-analytical solution and the fully numerical solution with Newmark’s time integration algorithm. This will allow for extension of the trilinear mechanical models to bidirectional horizontal motion, to time-varying vertical loads, to multi-degree-of-freedom-systems, as well to generalized models connected in parallel, where only numerical solutions are possible.

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Seismic Response and Hysteric Performance Analysis in Different Base Isolated Structures

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.639-640.891 ◽

2013 ◽

Vol 639-640 ◽

pp. 891-895

Author(s):

Ying Yuan ◽

Ai Hong Zhou ◽

Yan Li Gao

Keyword(s):

Energy Dissipation ◽

Performance Analysis ◽

Seismic Response ◽

Dynamic Responses ◽

Sliding Bearings ◽

Isolation System ◽

Hysteretic Performance ◽

Isolated Structures ◽

Rubber Bearings ◽

Isolated Systems

Firstly, the motion equation for parallel composite isolation system was formulated. Then, taking system with seven degree of freedoms for an illustrative example, the nonlinear dynamic responses of ordinary aseismic system, isolation system with friction sliding bearings, isolation system with laminated rubber bearings and parallel composite isolation system with the above combined bearings were calculated. Finally, the seismic responses of the above four structures were compared and discussed comprehensively and systematically, and the hysteretic performance of isolated floor was investigated. The results show that the isolation effect of isolated systems compared with the ordinary aseismic system is very notable and the hysteretic energy dissipation performance of isolated structures is excellent.

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