悬臂梁式动力吸振器多频减振研究

Vibration Reduction Effect of Cantilever Type Vibration Absorbers in Multi-frequency Band

将悬臂梁作为动力吸振器附加在振动主结构上来达到振动抑制的目的,数值计算分析表明悬臂梁式动力吸振器具有多频减振特性。按照模态理论建立基于悬臂梁的具有集中参数的等效复式动力吸振器模型,悬臂梁的每一阶模态作为一个自由度的弹簧质量系统,把悬臂梁每阶模态的有效模态质量和等效模态刚度作为每一自由度弹簧质量系统的集中质量和刚度。用悬臂梁式动力吸振器的附加动刚度验证等效复式动力吸振器模型的正确性。将悬臂梁式动力吸振器附加在主梁末端,调谐悬臂梁式动力吸振器的前4阶模态达到对主悬臂梁的多频减振效果,证实了悬臂梁式动力吸振器多频减振特性。

Cantilever type dynamic vibration absorbers can be attached to the principal structure to suppress vibration effectively.Numerical analysis shows that the cantilever type absorbers have multi-band vibration reduction characteristics.In this paper,the equivalent multiple spring-mass oscillator system model of the cantilever type dynamic vibration absorber is established according to the modal superposition theory.Each mode of the cantilever type dynamic vibration absorber is treated as a single DOF spring-mass oscillator system.The effective modal mass and effective modal stiffness of each mode are treated as the lumped mass and stiffness of the equivalent multiple spring-mass oscillator system.The correctness of the multiple spring-mass oscillator system model is verified by dynamic stiffness test of the cantilever type absorber.Finally,the cantilever type dynamic vibration absorber is attached to the end of the principal beam,and the first4modes of the absorber are found to reach the effect of multi-band vibration reduction.