Component and shaking table tests for full-scale multiple friction pendulum system

Tsai, C. S.; Chen, Wen-Shin; Chiang, Tsu‐Cheng; Chen, Bo‐Jen

doi:10.1002/eqe.598

Cited by 80 publications

(30 citation statements)

References 7 publications

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“…As shown in Figure 3, the hysteretic behavior is rigid linear with post-elastic stiffness equal to the sum of the effective radii of surfaces 2 and 3 and strength equal to the average coefficient of friction on these two surfaces. The behavior is identical to a double FP bearing with concave surfaces of equal radii and equal friction [18][19][20].…”

Section: Sliding Regime Imentioning

confidence: 92%

See 1 more Smart Citation

Spherical sliding isolation bearings with adaptive behavior: Theory

Fenz

Constantinou

2007

Earthq Engng Struct Dyn

209

144

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SUMMARYThe principles of operation and force-displacement relationships of three novel spherical sliding isolation bearings are developed in this paper. These bearings are completely passive devices, yet exhibit adaptive stiffness and adaptive damping. That is, the stiffness and damping change to predictable values at calculable and controllable displacement amplitudes. The primary benefit of adaptive behavior is that a given isolation system can be separately optimized for multiple performance objectives and/or multiple levels of ground shaking. With the devices presented here, this is accomplished using technology that is inherently no more complex than what is currently used by the civil engineering profession. The internal construction consists of various concave surfaces and behavior is dictated by the different combinations of surfaces upon which sliding can occur over the course of motion. As the surfaces upon which sliding occurs change, the stiffness and effective friction change accordingly. A methodology is presented for determining which surfaces are active at any given time based on the effective radius of curvature, coefficient of friction and displacement capacity of each sliding surface. The force-displacement relationships and relevant parameters of interest are subsequently derived based on the first principles.

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Section: Sliding Regime Imentioning

confidence: 92%

“…Equation (19) demonstrates that as soon as sliding starts on surface 4, it stops on surface 3. This can be proven by solving Equation (6) for u 3 with F = F f4 .…”

Section: Sliding Regime IIImentioning

confidence: 98%

Spherical sliding isolation bearings with adaptive behavior: Theory

Fenz

Constantinou

2007

Earthq Engng Struct Dyn

209

144

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“…This exponential function is the same proposed for PTFE (Constantinou et al 1990), and proves to also be applicable for the PET material even though the effect of velocity on friction is the opposite of that for PTFE. The friction coefficient of polymers is generally known to decrease during continuous loading, the effect being related to self-heating of the sliding interface (Stachowiak and Batchelor 2005), until a new thermal equilibrium condition is reached (Ettles 1987;Quaglini et al 2009). Figure 6 reports the trend of the friction coefficient over repeated cycling obtained by the Efficiency Test carried out at an average velocity of v = 200 mm/s for a total of 20 cycles with a 75 mm amplitude.…”

Section: Characterization Of the Pet Blendmentioning

confidence: 99%

Experimental assessment of sliding materials for seismic isolation systems

Quaglini

Dubini

Poggi

2011

Bull Earthquake Eng

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Novel self-lubricating materials are currently being proposed to be used in sliding isolation systems such as the curved surface sliding isolator system, or pendulum bearing system, for the protection of buildings and structures. The current codes for anti-seismic devices are focused on the evaluation of the performance of the whole isolation system; as a consequence, a reliable procedure for the pre-assessment of the material combinations of sliding interfaces is currently missing. Therefore in this paper, an experimental methodology is proposed for the characterization of self-lubricating materials through tests on small-scale specimens performed using customized equipment able to reproduce the operational conditions\ud of real isolation systems as per contact pressure, sliding velocity, temperature and slide path. The testing sequence has been designed in order to evaluate the sliding properties of the material in terms of static and dynamic coefficient of friction and wear resistance. Examples are reported for the assessment of two self-lubricating materials with different sliding characteristics.\ud In order to validate the method and to confirm the reliability of extrapolating the results to real working conditions, prototypes of pendulum isolation systems incorporating the assessed materials have been tested according to North American specifications and the relevant dynamic properties assessed from the Horizontal Load—Displacement loops. The experimental outcomes confirmed\ud that the frictional characteristics provided by the proposed procedure can be reliably used in the design of seismically isolated structure

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“…Among others, it is worth recalling the following factors that have contributed to the success of this technology: i) inherently low vibration frequency even when the mass pertaining to each isolator is not particularly high since the natural period primarily depends on the radius of curvature of the concave sliding surface rather than on the supported mass; ii) large displacement capability, limited only by the in-plane geometric dimensions of the device; iii) compact shape with considerably lower thickness than the elastomeric devices, a feature that makes them appealing for seismic retrofitting of existing structures; iv) theoretically zero residual displacements owing to the self-centering action induced by the pendulum operating principle; v) quite stable energy dissipation mainly controlled by the tribological properties of the sliding interfaces, a field on which material science has made significant progress in developing high performance materials with enhanced durability, mechanical and physical characteristics, see e.g. [12,15,19].…”

Section: Introductionmentioning

confidence: 99%

“…1, i.e., with the primary sliding surface on the top rather than on the bottom, however this different geometric layout does not affect the mechanical behavior of the device as a whole. Regardless of the geometric variants, the single CSS and the more recent advancements in double [9] and triple [19] CSS alike are highly flexible devices in the horizontal direction and stiff in the vertical one. The goal of this paper is to examine, from a numerical point of view, some aspects of the mechanical behavior of FP bearings.…”

Section: Introductionmentioning

confidence: 99%

Numerical Assessment of Concave Sliding Isolator’s Mechanical Behavior Under Bi-Directional Motion

Domenico¹,

Ricciardi²,

Benzoni³

2017

Proceedings of the 6th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COM

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Abstract. In this contribution, some aspects of the mechanical behavior of friction pendulum (FP) isolators are investigated from a numerical point of view. Attention is focused on the distinctive features observed in FP bearings when subjected to multi-directional excitations like those occurring in a real earthquake scenario. Due to the peculiarities related to the kinematics of the device and the curvature of the sliding surface, neglecting the bi-directional interaction and considering a uni-directional idealization would lead to underestimate the displacements expected during seismic events and to overestimate the dissipative capacity of the isolator accordingly. Furthermore, the resultant horizontal force of the FP bearing may differ markedly from what expected (and predicted by most numerical models) in the uni-directional case. This deviation is mainly ascribed to the geometrical features of the device itself. Additionally, the force-displacement behaviour of the FP bearing depends upon the coefficient of sliding friction, which is not constant as postulated by the simplified Coulomb model but varies during the course of an earthquake with sliding velocity, vertical load and, above all, repetition of cycles and consequent heating phenomena arising at the sliding interface. Among these effects, frictional heating has been recognized as the most important factor that affects the FP maximum displacement because it may induce significant friction degradation, consequently it should be properly considered in a truthful model of the FP bearing via a sophisticated coupled thermo-mechanical analysis.The aim of this paper is to scrutinize the above physical phenomena by means of a 3D finite element model. The developed model allows us to closely analyze the kinematics of the device, to assess the contact force distribution between the sliding surfaces and to examine certain nonlinear phenomena that become manifest especially during bi-directional excitations.

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Component and shaking table tests for full-scale multiple friction pendulum system

Cited by 80 publications

References 7 publications

Spherical sliding isolation bearings with adaptive behavior: Theory

Spherical sliding isolation bearings with adaptive behavior: Theory

Experimental assessment of sliding materials for seismic isolation systems

Numerical Assessment of Concave Sliding Isolator’s Mechanical Behavior Under Bi-Directional Motion

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