强超声脉冲激励下金属板超谐波和次谐波振动的有限元分析  

Finite element analysis of superharmonic and subharmonic vibrations of plates excited by intensive ultrasonic pulses

作　　者：陈赵江[1] 张淑仪[1] 

机构地区：[1]南京大学声学研究所近代声学实验室,南京210093

出　　处：《声学学报》2011年第2期102-112,共11页Acta Acustica

基　　金：国家自然科学基金资助项目(10574073)

摘　　要：针对实验中观察到金属板在强超声脉冲作用下的超谐波和次谐波振动现象,采用显式有限元方法建立有限元模型,并对其进行瞬态动力学分析。在模型中压电结构的热弹性类比方法和界面接触-碰撞算法分别用来模拟换能器激励以及变幅杆与板之间的相互作用。通过分析计算得到板的振动速度的波形和频谱以及接触力的波形和频谱,可知在换能器工作条件下,变幅杆与金属板之间的接触力波形畸变是导致板超谐波振动的原因,而变幅杆与金属板之间的间歇性接触运动引起板的次谐波振动,有限元数值模拟与实验结果相符。Based on the experimental observation of superharmonic and subharmonic vibrations of steel plates excited by intensive ultrasonic pulses,a finite element modeling is established and transient dynamic analyses are performed by an explicit finite element method.A piezoelectric-thermal analogy method and an interface contact-impact algorithm are used to simulate the high-power ultrasonic transducer excitation and the dynamical interaction between the transducer horn tip and the plate surface,respectively.By analyzing the vibration velocity waveforms,vibration frequency spectra and contact force time histories obtained in the simulations,it can be found that the waveform distortion of the contact forces between the horn tip and the plate surfaces is the main reason for the generation of the superharmonic vibrations. On the other hand,the intermittent contact between the horn tip and the plate is the reason for subharmonic vibrations in the plates.The numerical simulations agree with that of the experimental results.

关 键 词：谐波振动 金属板 脉冲激励 有限元分析 超声 有限元数值模拟 瞬态动力学分析 有限元模型 

分 类 号：O426[理学—声学]