PDF《Based on Microcantilever》

Hans Journal of Civil Engineering 土木工程, 2013, 2, 151-155 http://dx.

doi.org/10.12677/hjce.2013.22026 Published Online May

2013 (http://www.hanspub.org/journal/hjce.html) Near-Field Dynamic Non-Destructive Detection Simulation Based on Microcantilever Chunjuan Zhang, Feng Wang Department of Mechanics, Chongqing Energy College, Chongqing Email: 632721610@qq.com Received: Dec. 11th , 2012;

revised: Jan. 11th , 2013;

accepted: Jan. 26th ,

2013 Copyright ?

2013 Chunjuan Zhang, Feng Wang. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract: An ultrasonic near-field dynamic non-destructive detection method based on Microcantilever is proposed to receive ultrasonic wave, and dynamic response of the near-field scattering of waves from Ultrasonic transducer using microcantilever receiver can be known with FET software COMSOL Multiphysics. The receiver scans the surface point by point and approaches the defect, when the receiver is just ahead of the defect, and the amplitude shows its maximum peak-to-peak value. The changes in the amplitude come from the near-field surface wave interaction with the free boundary of the defect wall. By contrast with experimental results, feasibility of the simulation method is demonstrated, which will contribute to deeper theoretical research on defect location of the micro-components, affording the reference for the follow- up experimental design. Higher resolution is obtained by changing the thickness of the cantilever or adopting more higher order frequency in order to test nano-defects. Keywords: Microcantilever Transducer;

Acoustic Non-Destructive Detection;

Finite Element Simulation;

COMSOL;

Atomic Force Microscopy 基于微悬臂梁的近场动态无损检测仿真 张春娟,王锋重庆能源职业学院机械工程系,重庆 Email: 632721610@qq.com 收稿日期:2012 年12 月11 日;

修回日期:2013 年1月11 日;

录用日期:2013 年1月26 日摘要:提供了一种用于近场无损检测研究的采用微悬臂梁进行接收超声波的动态检测技术,借助 COMSOL Multiphysics 有限元软件模拟了微悬臂梁传感器接收由超声换能器所产生的超声波的动态响应. 在进行逐点扫描 时,探针针尖恰好在微缺陷上方时,振幅达到其最大值.并与试验结果进行对比,验证了该模拟方法的可行性, 有助于对微器件缺陷精确的定性、定量表征作更深一步的理论研究,为后续的实验设计提供了参考,对更加微 小的缺陷的检测,可通过改变微悬臂梁厚度或采用更高阶次的悬臂梁以增加谐振频率来实现. 关键词:悬臂梁传感器;

超声无损检测;

有限元仿真;

COMSOL;

原子力显微镜 1. 引言 微悬臂梁结构在微观领域有着广泛的应用,特别 是电子产品高集成度与高性能化的发展,对超精表面 和亚表面无损伤性要求越来越高,悬臂梁动态无损检 测技术以点接触的方式能够实现微米级缺陷的快速 在线扫查.而传统的检测方法需要使用专门的耦合剂 来减少超声波在空气中传播的损失而使样品受到污 染;

而且样品如果在高温或几何结构要求严格如几何 Copyright ?

2013 Hanspub

151 基于微悬臂梁的近场动态无损检测仿真 尺寸及其微小、弯曲程度大、在线检测的情况都限制 了它的适用范围,而悬臂梁动态无损检测技术较好地 弥补了这方面的不足. 微悬臂传感器是基于原子力显微镜[1] (AFM)的工 作原理而设计的一种新型传感器件,具有结构简单, 质量轻,频带宽,检测灵敏度高及声阻抗易匹配等特 点,可用于近场或微器件的检测.由于微悬臂传感器 的谐振频率可以通过改变其几何尺寸(包括长度和厚 度)、分辨率(探针的曲率半径)或选择合适的材料得到 提高,因此,我们根据理论分析的结果,在有限元软 件中进行模拟传感器的动态性能,得到适合超声接收 的传感器的各项参数,有助于提高检测灵敏度和精 度,对薄膜材料粘弹性性质的确定,结构缺陷的无损 检测,以及微器件的制作与微动疲劳的研究,有着重 要的科学意义及学术价值,为超声无损检测技术发展 提供了新的实验手段. 2.实验装置 2.1. 基频检测 采用原子力显微镜进行相关参数的检测,其检测 原理为微悬臂梁的弯曲使得光路发生变化,利用激光 探测器可以检查到这种变化,然后经信号放大器进行 处理. 首先,测量微悬臂梁的无接触时的振动频率,实 验装置如图