力学共振吸收谱探测耦合振动模式  

Detection of a coupled vibration by mechanical resonant absorption spectra

作　　者：杨岳彬[1] 左文龙[2] 保延翔[3] 刘树郁[1] 李龙飞[2] 张进修[2] 熊小敏[2] 

机构地区：[1]中山大学信息科学与技术学院,广州510006 [2]中山大学物理科学与工程技术学院,光电材料与技术国家重点实验室,广州510275 [3]中山大学东校区教学实验中心,广州510006

出　　处：《物理学报》2012年第20期145-150,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10974259);中央高校基本科研业务费(批准号:091gpy29)资助的课题~~

摘　　要：提出探测复杂力学振动系统耦合振动模式的方法:通过测量力学振动系统中某一易于探测的振动模式对外力的响应行为,在该振动模式应变落后于应力的相位差-频率谱(表观机械能耗散-频率谱)中,除了能观察到与被测量振动模式本征频率所对应的相位变化外,与被测量振动模式耦合的其他振动模式也表现为共振吸收峰;从共振吸收峰的性质,如峰位、峰宽、峰高等可以得到相应耦合振动模式的本征频率、损耗以及耦合强度等信息.以倒扭摆力学系统为例,通过测量扭摆的扭转振动模式应变落后于应力的相位差-频率谱研究了扭摆系统中摆杆的进动振动模式.In this paper, we propose a novel scheme of measuring a coupled but uneasy detected vibration mode through surveying another much easier detected vibration mode in a complex mechanical system. Through measuring the frequency dependence of phase lag of strain behind stress, i.e., the apparent mechanical dissipation-frequency spectrum, for the easy detected vibration mode, we are able to obtain the corresponding resonant absorption peak for the coupled vibration mode in addition to the expected main system resonance. By studying the observed resonant absorption peak： peak position, peak width and peak height, we can obtain the detailed information about the coupled vibration mode： the intrinsic resonant frequency, dissipation and coupling coefficient. Through measuring the apparent mechanical dissipation frequency spectrum of torsion vibration, the detection of the progression vibration about the pendulum axis is presented as a representative example of our scheme.

关 键 词：共振吸收峰 相位差-频率谱 耦合 振动模式 

分 类 号：O321[理学—一般力学与力学基础]