Experimental validation of a simplified model for rolling isolation systems
Experimental validation of a simplified model for rolling isolation systems
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DOI：
10.1002/eqe.2387
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发表时间：
2014-06-01
影响因子：
4.5
通讯作者：
Gavin, Henri P.
中科院分区：
文献类型：
--
作者：
Harvey, P. Scott, Jr.;Zehil, Gerard-Philippe;Gavin, Henri P.
滚动隔震系统(RISS)通过将振动敏感对象的动态响应与水平楼层运动分离，保护关键任务设备和宝贵财产免受地震危害。这些反应包括限制钢球在碗形表面之间滚动。在钢板之间滚动钢球时，可以通过在钢板上粘贴薄橡胶片来增加钢球的轻阻尼，从而增加滚动阻力，降低对RIS的位移要求。要评估轻度和重度阻尼RISS减轻地震引起的故障风险的能力，需要高保真的模型来充分捕捉系统的内在非线性行为。本文提出的简化模型适用于具有任意势能函数的RISS，既适用于轻阻尼RISS，也适用于重阻尼RISS，并通过对大范围扰动频率和强度的峰值响应的成功预测得到了验证。因此，验证后的模型可以用来计算位移需要等能力的峰值楼板运动的谱。将这些谱与美国土木工程师学会提供的具有代表性的楼层运动谱进行了比较。根据运动周期的不同，在粘弹性薄板之间滚动提供的阻尼会使允许的地板运动强度增加2-3倍。以这种方式提供阻尼的隔震系统的加速度响应不会随着阻尼值的增加而增加，即使是在短周期激励下也是如此。版权所有(C)2013 John Wiley&Sons，Ltd.
Rolling isolation systems (RISs) protect mission-critical equipment and valuable property from earthquake hazards by decoupling the dynamic responses of vibration-sensitive objects from horizontal floor motions. These responses involve the constrained rolling of steel balls between bowl-shaped surfaces. The light damping of steel balls rolling between steel plates can be augmented by adhering thin rubber sheets to the plates, thereby increasing the rolling resistance and decreasing the displacement demand on the RIS. An assessment of the ability of lightly- and heavily-damped RISs to mitigate the hazard of seismically induced failures requires high-fidelity models that can adequately capture the systems' intrinsic nonlinear behavior. The simplified model presented in this paper is applicable to RISs with any potential energy function, is amenable to both lightly- and heavily-damped RISs, and is validated through the successful prediction of peak responses for a wide range of disturbance frequencies and intensities. The validated model can therefore be used to compute the spectra of peak floor motions for which displacement demands equal capacity. These spectra are compared with representative floor motion spectra provided by the American Society of Civil Engineers 7-10. The damping provided by rolling between thin viscoelastic sheets increases the allowable floor motion intensity by a factor of 2-3, depending on the period of motion. Acceleration responses of isolation systems with damping supplied in this fashion do not grow with increased damping, even for short-period excitations. Copyright (c) 2013 John Wiley & Sons, Ltd.