摘要
在声发射的应用场所中,采集的声发射信号很多都经过界面传输。主要研究构成不连续界面的两个构件尺寸对信号传输的影响,利用小波包技术分析信号在不同频率范围内的衰减特性。研究表明,不连续界面对信号存在衰减,构成界面的构件相对尺寸的大小对衰减影响较大,构件尺寸相差较大时,由于波在小构件上的多次反射作用,使得采集信号能量反向增强,信号畸变程度增大。建议在经过界面采集信号时,尽量选择在构件相对尺寸相当且结构较简单的部位进行。
Acoustic emission (AE) signals transmit across interfaces in many applications. This paper studies the effects of sizes of two structures forming a discontinuous interface on signals propagation. And the wavelet packet technique is used to analyze attenuation characteristics of signals in different frequency bands. The experimental results indicate that interface has effects on attenuation and the relative size of structures is one of the main factors. The signal energy is strengthened due to multiple reflections of signals on the small-size structure when the sizes of structures are very different. And the collected signals are distorted worse than the original signals. So it is a better way to mount sensors on the simpleer structure with a size as much as that of the structure with AE sources when signals are collected across interfaces.
出处
《振动与冲击》
EI
CSCD
北大核心
2008年第9期139-141,共3页
Journal of Vibration and Shock
基金
国家自然科学基金资助项目(No.50465002)
关键词
衰减
声发射
小波包
界面
attenuation
acoustic emission
wavelet packet
interface
