Studies of An Innovative Nonlinear Actuator for the Semiactive Control of Dispersed Civil Structures

目前用于产生控制力的执行机构通常不足以限制土木结构在强烈地震下的反应。目前迫切需要一种新一代的执行器，这种执行器能够在强烈的地面运动下充分发挥作用，从而引起结构的显著非线性变形。本研究的目的是开发一种创新的半主动阻尼增强装置，以控制分散土木结构的地震反应。控制过程使用非线性辅助质量阻尼器，其具有可调（自适应）运动限制止点，位于整个结构的选定位置，通过打乱振幅积累的有序过程，在结构动态响应中注入最优量的“混沌”。各半主动非线性作动器附近结构的振动程度决定了作动器的主动控制间隙大小和激活时间。通过使用控制能量来调整执行器的关键参数，而不是直接衰减结构的运动（传统的主动控制方法是这样做的），在完成给定水平的振动控制所消耗的总能量方面取得了显着的改善。此外，还将进行一系列的分析和实验研究，这些分析和实验研究将采用具有若干创新非线性致动器的桥梁模型，并受到地震振动器的多支承地震激励。＊＊＊

9703805 Masri Presently used actuators to generate control forces are generally inadequate for limiting the response of civil structures under strong earthquake shaking. There is a critical need for a new generation of actuators that have the capability of adequately performing under strong ground motion which may induce significant nonlinear deformations in structures. The objective of this research is to develop an innovative semi- active damping augmentation device for controlling the seismic response of dispersed civil structures. The control procedure uses nonlinear auxiliary mass dampers with adjustable (adaptive) motion-limiting stops, located at selected positions throughout the structure, to inject an optimum amount of "chaos" in the structures dynamic response by disorganizing the orderly process of amplitude buildup. The degree of the structure's oscillation in the vicinity of each semiactive nonlinear actuator determines the actuator's actively-controlled gap size and activation time. By using control energy to adjust the actuator's critical parameters instead of directly attenuating the motion of the structure (which conventional active control methods do), a significant improvement is achieved in the total amount of energy expended to accomplish a given level of vibration control. A sequence of analytical and experimental studies by means of a bridge model to be provided with several innovative nonlinear actuators and subjected to multiple-support earthquake excitation by seismic shakers will also be conducted. ***