Response of sliding structures to bi-directional excitation
Response of sliding structures to bi-directional excitation
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DOI：
10.1006/jsvi.2000.3476
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发表时间：
2001-06
影响因子：
4.7
通讯作者：
R. S. Jangid
中科院分区：
文献类型：
--
作者：
R. S. Jangid
摘要 研究了滑动系统支撑的结构对双向（即两个水平分量）地震和谐波地震动的动态响应。假设上部结构是刚性的，并且假设滑动系统界面处的摩擦力具有理想的库仑摩擦特性。使用纽马克迭代法以增量形式求解具有滑动系统的结构在两个正交水平方向上的运动耦合微分方程。由于摩擦力对系统响应的依赖性，需要进行迭代。将具有双向相互作用的系统的响应与没有相互作用的系统的响应（即两个方向的二维理想化）进行比较，以研究摩擦力双向相互作用的影响。这些影响是在重要的参数变化下进行研究的。考虑的重要参数包括隔离器特性（即周期、阻尼和摩擦系数）和谐波激励特性（即激励频率、幅值比和相位差）。结果表明，如果忽略摩擦力双向相互作用的影响，那么滑动基座位移将被低估，这从设计的角度来看至关重要。此外，与有恢复力的系统相比，没有恢复力的滑动系统的双向相互作用效应更严重。
Abstract Dynamic response of structures supported on the sliding systems to bi-directional (i.e., two horizontal components) earthquake and harmonic ground motion is investigated. The superstructure is assumed to be rigid and the frictional forces mobilized at the interface of sliding system are assumed to have the ideal Coulomb-friction characteristics. Coupled differential equations of motion of the structure with sliding system in two orthogonal horizontal directions are solved in the incremental form using Newmark's method with iterations. The iterations are required due to dependence of the frictional forces on the response of the system. The response of the system with bi-directional interaction is compared with those without interaction (i.e., two-dimensional idealization in two directions) in order to investigate the effects of bi-directional interaction of frictional forces. These effects are investigated under important parametric variations. The important parameters considered include the isolator properties (i.e., period, damping and friction coefficient) and the characteristics of the harmonic excitation (namely excitation frequency, amplitude ratio and phase difference). It is shown that if the effects of bi-directional interaction of frictional forces are neglected then the sliding base displacements will be underestimated which can be crucial from the design point of view. Further, the bi-directional interaction effects are found to be more severe for the sliding systems without restoring force in comparison with the systems with restoring force.