磁约束阻尼的减振机理

采用在约束层端部上设置永磁体的新方法可使阻尼层获得比传统约束阻尼处理方法更高的剪应变，从而增强粘弹层的阻尼耗能。本文应用Hamilton原理，考虑永磁体的影响，推导了对称双层夹心悬臂梁的运动方程，对模型进行了实验验证；分析了一阶共振时，永磁体对共振振幅、阻尼层剪应变、约束层作用力的影响，阐明了新型的磁机敏约束阻尼方法的减振机理。

Vibration Attenuation Mechanism of Magnetic Constrained Layer Damping Treatment

The shear strains in visoelastic damping layers resulting from the attraction arrangement magnets at the constraining layers end are higher than that in the conventional passive constrained damping layer(PCLD).Therefore,significant improvement of the damping characteristics can be achieved by using magnetic constrained layer damping(MCLD) treatment.In the paper,an analytical method is developed to study the influence of a new magnetic constrained treatment on vibration characteristics of a double sandwich-type cantilever beam.The differential equations of motion are derived by employing Hamilton's principle.The method is validated experimentally.The influence of magnetic force on resonance amplitude,shearing strains and force acting on constraining layers are discussed.Such study is helpful to understand the vibration attenuation mechanism of magnetic constrained layer damping treatment.