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原文传递 Seismic Protection of Highway Bridges with Negative Stiffness Devices

题名：	Seismic Protection of Highway Bridges with Negative Stiffness Devices
作者：	Attary, N.; Symans, M. D.; Nagarajaiah, S.; Reinhorn, A. M.; Constantinou, M. C.; Sarlis, A. A.; Pasala, D. T. R.; Taylor, D. P.
关键词：	Seismic protection##Highway bridges##Control devices##Precompressed targets##Seismic demands##Numerical simulations##Implemention##
摘要：	A new control devices has been developed and implemented for seismic response control of highway bridges. the device produces negative stiffness in a completely passive manner via a mechanical mechanism. Numerical simulations and experimental shaking table tests have demonstrated the effectiveness of the device in limiting the seismic demands on bridge structures. The main feature of the negative stiffness device is a pre-compressed spring, which can push the structure away from its center position and thus induce negative stiffness. When implemented in parallel with a structure having positive stiffness, the combined system appears to have substantially reduced stiffness while remaining stable. Thus, there is an 'apparent weakening' of the structure that results in an 'apparent yield point,' reduced forces and increased displacements. The increase in displacement response can be limited by incorporating a damping device in parallel with the negative stiffness device or by adding friction to the device assembly. In the report, the negative stiffness devices are described along with their hysteretic behavior as obtained from a series of cyclic tests that were utilized to calibrate the parameters of a numerical model. In addition, results from numerical simulations and seismic testing of a quarter-scale bridge model are presented wherein the bridge was configured with various isolation system components (isolation bearings, negative stiffness devices, and viscous dampers). In addition, the bridge was designed to mimic either a single-span bridge supported on abutments or an interior span of a multi-span bridge. The results of the investigation clearly demonstrate the effectiveness of the negative stiffness devices in limiting the seismic response of the bridge for multiple bridge configurations.
总页数：	254
报告类型：	科技报告