%0 Journal Article
%T Low pass effect of surface defect metal based on laser ultrasonic<br>利用激光超声技术研究表面微裂纹缺陷材料的低通滤波效应
%A Wang Jing-Shi
%A Xu Xiao-Dong
%A Liu Xiao-Jun
%A Xu Gang-Can
%A <br>王敬时
%A 徐晓东
%A 刘晓峻
%A 许钢灿
%J 物理学报
%D 2008
%I 
%X The travelling properties of laser-generated surface acoustic wave with broad bandwidth, which propagated on a sample with surface defects, have been investigated in theory. The numerical results of theoretical models with different defects indicate that the surface defects worked as low-pass filter for the travelling surface acoustic waves. The cut-off frequency of low-pass filter is linearly related to the depth of the defect, and decreased against the increasing depth of the defect. The amplitude of the travelling surface acoustic wave is seriously attenuated with increasing width of surface defect. The numerical results provide a theoretical basis for quantitative detection of the surface defects.
%K laser ultrasonic
%K surface acoustic wave
%K finite element method
%K low-pass filter<br>激光超声，
%K 声表面波，
%K 有限元方法，
%K 低通滤波器
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=6E709DC38FA1D09A4B578DD0906875B5B44D4D294832BB8E&cid=47EA7CFDDEBB28E0&jid=29DF2CB55EF687E7EFA80DFD4B978260&aid=23F7C1AAD2E6CE265067E1315E9D0B1E&yid=67289AFF6305E306&vid=11B4E5CC8CDD3201&iid=59906B3B2830C2C5&sid=41E839298DD99ADE&eid=540A06722B7E5791&journal_id=1000-3290&journal_name=物理学报&referenced_num=1&reference_num=0