试样激励下轻敲模式原子力声显微镜的非线性动力学特性

发布时间：2018-04-13 00:12

本文选题：微悬臂梁 + 激励幅值　；参考：《声学学报》2016年05期

【摘要】：利用Euler-Bernoulli梁理论和DMT针尖-样品作用力模型建立了试样激励下轻敲模式原子力声显微镜(AFAM)系统的动力学方程,并应用非线性动力学分析方法对AFAM微悬臂梁的振动特性进行研究。通过合理改变超声激励幅值、超声激励频率和针尖-样品初始间距等模型参数模拟得到微悬臂梁的超谐波、次谐波、准周期和混沌振动现象,采用时间序列、频谱、相空间、Poincare截面和Lyapunov指数等方法对不同非线性振动特性进行表征。通过分析不同模型参数条件下微悬臂梁针尖-样品作用力特性,探索了微悬臂梁不同非线性振动现象的产生机制。此外,研究了AFAM微悬臂梁运动的分岔特性,发现当超声激励幅值和针尖-样品初始间隙连续变化时,周期、准周期和混沌运动交替出现。研究结果对AFAM系统非线性动力学行为分析和混沌振动控制提供了理论参考。
[Abstract]:Based on the Euler-Bernoulli beam theory and the DMT tip sample force model, the dynamic equations of the light knock mode atomic force microscope (AFAM) system are established, and the vibration characteristics of the AFAM microcantilever beam are studied by nonlinear dynamic analysis method.The ultra-harmonic, sub-harmonic, quasi-periodic and chaotic vibration phenomena of the micro-cantilever beam are simulated by changing the ultrasonic excitation amplitude, the ultrasonic excitation frequency and the initial distance between the tip and the sample. The time series and frequency spectrum are used to simulate the ultra-harmonic, sub-harmonic, quasi-periodic and chaotic vibration phenomena of the micro-cantilever beam.The phase space Poincare cross section and Lyapunov exponent are used to characterize different nonlinear vibration characteristics.The mechanism of different nonlinear vibration phenomena of micro cantilever beam was investigated by analyzing the force characteristics of tip and sample of micro cantilever beam under different model parameters.In addition, the bifurcation characteristics of AFAM micro-cantilever beam are studied. It is found that when the ultrasonic excitation amplitude and the initial gap between the tip and the sample change continuously, the periodic, quasi-periodic and chaotic motion alternates.The results provide a theoretical reference for nonlinear dynamic behavior analysis and chaotic vibration control of AFAM system.
【作者单位】：浙江师范大学数理与信息工程学院;中国科学院声场声信息国家重点实验室;近代声学教育部重点实验室南京大学声学研究所;
【基金】：国家自然科学基金项目(11304286,11274279,11174255)资助
【分类号】：TH742

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