A Study on Vibration Suppression Devices Using a Giant Magnetostrictive Material

在本研究中，为了获得在振动抑制效果上上级被动阻尼器的机械阻尼器，开发了两种滚珠丝杠型阻尼器：一种是由滚珠丝杠、超磁致伸缩驱动器、制动盘、一种是由半主动阻尼器和滚珠丝杠式稀土磁阻尼器组成的混合型阻尼器。制作了两种阻尼器，并利用电液式振动台测试了两种阻尼器支撑的简支梁（铜管）的地震反应。实验结果表明，输出速度反馈控制的情况下是最有效的抑制梁的最大挠度和减少阻尼器的阻力。在此基础上，采用半主动阻尼器时，梁的最大挠度减小到无阻尼器时的1/18左右，采用混合阻尼器时，梁的最大挠度减小到无阻尼器时的1/70左右。实验结果表明，模型3层处的最大加速度减小到非隔振时的1/3-1/5;采用超磁致伸缩作动器和圆盘-质量块系统组成新型激振器，测量了激振器的频率响应。在本实验中，激振力的控制是通过反馈控制，以获得一个恒定的激振力在30- 100赫兹。结果，证实了该激励器也可以用于主动质量阻尼器。

In this research, two kinds of ball screw-type dampers have been developed in order to obtain mechanical dampers which are superior in the effects of vibration suppression to passive dampers : one is a semiactive damper consisting of a ball screw, giant magnetostrictive actuators, a break disk (an aluminium disk) and brake shoes, and the other is a hybrid damper which is united the semiactive damper and a ball screw-type magnetic damper using rare-earth magnets. Two kinds of dampers were made, and earthquake responses of a simple beam (a copper pipe) supported with each damper were measured using an electro-hydraulic type shaking table. The experimental results show that the case of the output velocity feedback control is most effective both for suppressing the maximum deflection of the beam and for reducing the resisting forces of the dampers. In this case, the maximum deflection of the beam decreases to about 1/18 by using the semiactive damper and to about 1/70 by using the hybrid damper compared with the case of without damper.Next, a 3-story building model isolated by the hybrid damper and a coil spring was made, and the earthquake responses of the base-isolated building model were measured. The experimental results show that the maximum acceleration at the 3rd story of the building model decreases to 1/3-1/5 to that of the nonisolated one.A new type of vibration exciter consisting of a giant magnetostrictive actuator and a disk-mass system was also made, and the frequency responses of the exciter were measured. In this experiment, the exciting force was controlled by feedback control in order to obtain a constant exciting force within 30-100Hz. As a result, it was confirmed that this exciter can be also used for an active mass damper.