一种新型的MR隔震减振支座及其剪切性能试验研究

基于磁流变(MR)智能材料的减振器技术的研究可以为实现工程结构隔震减振自适应控制开辟一条新的途径。设计加工了一种新型的分体式MR隔震减振支座,并对该隔震减振支座的剪切性能进行了试验研究。新型MR隔震减振支座包含MR塑性体工作单元和MR弹性体工作单元,其中MR塑性体提供小位移工况时的刚度和阻尼,MR弹性体提供大位移工况时的刚度和阻尼。结果表明:新型MR隔震减振支座的剪切刚度随着工作电流强度的增大而增大,相较无电流工况,电流强度为2A时等效剪切刚度相对变化率可达到50%以上;无电流输入时支座中基体及普通填充橡胶仍可提供一定阻尼力,能够有效吸收振动能量,达到中高阻尼橡胶支座的性能;竖向压应力提高了新型MR隔震减振支座的剪切刚度;小位移时加载频率的降低对新型MR隔震减振支座的剪切刚度有增益效果。该新型MR隔震减振支座可以适用于震动荷载工况复杂多变,需要严格控制大位移变形的隔震结构物。

A Novel MR Isolation and Damping Support and Its Shear Performance Test Study

Vibration damper technology based on Magnetorheological (MR) smart materials can open up a new way to realize adaptive control of vibration isolation for engineering structures. In this paper, a novel split-type MR isolation and damping support is designed and manufactured, and the shear performance of the isolator is experimentally studied. The novel MR isolation and damping support includes the MR plastic body working unit and the MR elastomer working unit, in which the MR plastic body provides the stiffness and damping under the small displacement condition and the MR elastomer provides the stiffness and damping under the large displacement condition. The results show that the shear stiffness of the novel MR isolation and damping support increases with the increase of working current intensity, and the relative change rate of the equivalent shear stiffness can exceed 50% when the current intensity is 2A compared with no working current condition. Without the current intensity, the base matrix and the ordinary filled rubber can still provide a certain damping force, and the vibration energy can be effectively absorbed. The performance of the MR support is equivalent to that of medium and high damping rubber supports. The vertical compressive stress improves the shear stiffness of the MR supports. The decrease of the loading frequency at the small displacement has the gain effect on the shear stiffness of the novel MR support. The proposed novel MR isolation and damping support can be applied to the complicated and varied vibration loading conditions, and the isolated structures with strict large displacement controls.