基于平移不变小波的声发射信号去噪研究

小波阈值去噪算法在信号的奇异点处会产生Pesudo-Gibbs现象。平移不变小波去噪方法是对闽值法的改进，该方法可以有效地抑制Pesudo-Gibbs现象，而且能够减少原始信号和估计信号的均方根误差，提高信噪比。将该方法用于声发射信号的去噪处理，并与闽值法进行了比较。仿真结果表明该研究方法可以有效地去除噪声，提取声发射信号的特征信息，具有较强的工程实用性。     

Use of Amplitude Distribution Parameters of Acoustic Emission Signals for Assessing the Strength of Structural Materials

The development of efficient nondestructive testing methods is based on a search for correlations between parameters of the condition of a tested object and measurable diagnostic parameters. In this work, we consider the information value of the amplitude distribution and type of time dependences of the number of acoustic emission pulses at the fine fracture stage that precedes the formation of a macrodefect or a next crack pop-in. The statistical parameters of the amplitude signal distribution are used in methods for long-term forecasting of mechanical damage.     

FPGA在声发射参数提取中的应用

根据声发射信号参数提取的特点,介绍了应用现场可编程门列阵FPGA（Field programmable Gate Array）的提取声发射参数的一种方法,给出了用VHDL语言来描述其功能的流程图,并进行了实验仿真,结果证明该方法能够有效地提取声发射信号的特征参数。     

Magnetoelastic Acoustic Emission in Ferromagnetic Materials. II. Effect of Elastic and Plastic Strains on Parameters of Magnetoelastic Acoustic Emission

The action of tensile and compressive stresses on iron, nickel, and steel crystals of different quality in the process of magnetization is considered. A clear relation between the parameters of magnetoelastic acoustic emission (MAE) on one side and, on the other, the processes of reshaping of 90°, 71°, and 109° magnetic domains, change in their volume fraction, and mobility of the domain walls is revealed. The dependence of the behavior of the magnetic properties of ferromagnets, namely, the coercive force, longitudinal and transverse magnetostriction, and induction, on the MAE parameters is also established. It is shown that under certain conditions of magnetization the MAE parameters can be used more successfully than the coercive force of ferromagnets for testing their stressed-strained state.     

声发射(AE)信号在砂轮钝化程度检测中的应用

本文利用声发射（AE）信号的归原处理法，在线监测小批量、多品种磨削过程砂轮钝化程度，利用该方法可以克服仅靠监测AE信号幅值变化不能监测工件材料、加工要求和磨削参数经常变化环境下砂轮钝化程度的缺陷；实验结果表明，声发射（AE）信号的归原处理法能够有效监测砂轮的钝化。     

Criterion Parameters for Assessing Degradation of Composite Materials by Acoustic Emission Testing

Russian Journal of Nondestructive Testing - A concept of monitoring the degree of degradation in the multilayered structure of polymer composite package has been developed at the laboratory for...     

声发射参数提取新解决方案的初步探讨

阐述了通过设计FPGA(Field Programmable GateArray)现场可编程门列阵来提取声发射参数的一种方法，它是通过用VHDL语言来描述其功能的，还设计了具体的流程图，并进行了实验仿真，初步结果让人满意。     

Influence of The Passband of Frequency Filters on the Parameters of Acoustic Emission Pulses

Russian Journal of Nondestructive Testing - To study the effect of the passband of a digital filter on the nature of the attenuation of the amplitude of an acoustic emission (AE) pulse and on the...     

基于MATLABGUI的声发射信号特征参数分析平台

文章在MATLABGUI编程的基础上,设计了基于MATLAB．GUI的声发射信号特征参数分析平台。该平台用于分析混凝土构件在损伤状况下释放的有效声发射信号参数随时问或外变量变化的情况,从而得到声发射源的活动情况和发展趋势。仿真试验表明,该平台能够反映出预应力混凝土构件破坏过程中的特征信息,为实际远距离在线结构健康的监测提供了实际依据。     

Use of the Acoustic Emission Method for Detecting Corrosive Damages of Technological Pipelines

An example of testing a technological pipeline using the acoustic emission method is described. Increased corrosive activity zones are detected and an attempt of estimating the sources with the use of criteria which have not been used earlier for estimating the corrosive attack (local dynamic Ivanov–Bykov criterion) is made.     

压力容器上声发射源的新型定位方法

压力容器裂纹扩展时产生的弹性波在传播时声压遵从指数衰减规律,本文提出一种利用声衰减对声发射源进行源定位的新方法。用AE21C型声发射仪对自制的小型高分子合成纤维材料容器以铅笔芯折断产生信号为模拟源进行了实验测量,证明这种新的源定位方法可行,并具有无须测量传播介质衰减特性、无须测量声速等优点。     

Analysis of Acoustic Signals for Diagnostics of Composite Materials

Journal of Machinery Manufacture and Reliability - This article presents a method for the analysis of diagnostic acoustic signals for defect detection in composite materials. For this purpose, a...     

Diagnostics of Spacecraft Launching Facilities Using Acoustic Testing Techniques

Improving quality and reliability of materials, components, and structures is one of topical problems in the contemporary science and technology. These properties are especially important for devices and structures operating under extreme conditions: under high static and dynamic loads, in contact with aggressive and hazardous media. Reliability of airspace, chemical, nuclear, and other facilities operating under critical conditions essentially depends on structural materials that are used in stressed components of such structures [1].     

Use of Acoustic Emission in Testing Bottoms of Welded Vertical Tanks for Oil and Oil Derivatives

Basing on the reports on AE testing by Physical Acoustics Ltd. as well as laboratory and field experiments by OAO Slavneft'–Megionneftegaz, a technique has been developed for AE tests of bottoms of welded vertical tanks (WVTs) for oil and oil derivatives. This approach allows the engineers to assess rapidly conditions of WVT bottoms without interrupting their operation by measuring the corrosive activity of AE sources. Empirical functions describe the average activity of AE sources versus the rate of local corrosion in tanks build for various purposes and strongly damaged by corrosion, which is the major cause of leaks in bottoms of WVTs for oil and oil derivatives.     

Effect of Loading Conditions on Informative Parameters and Signal Spectra of Acoustic Emission in Samples of Carbon Steels

Parameters and spectra of acoustic emission (AE) signals generated by the static and fatigue fracture of planar samples of 45 and St3 steels have been studied. Distortions in the structure of AE signals caused by their propagation through samples have been investigated, and the feasibility of accurate determination of informative parameters has been tested. The degree of hazard due to a aw has been estimated in experiments basing on the recorded AE energy.     

工业烟道固体颗粒物排放量自动监测方法

工业烟道是大气中悬浮颗粒物的主要排放源，这些悬浮颗粒物对人体健康产生直接的负面影响，受到各国政府及有关研究部门的高度重视。在线监测工业烟道固体颗粒的质量排放量对遏制污染源，保护大气环境具有重要作用。固体颗粒质量排放量与固体颗粒排放浓度、速度密切相关。针对我国目前新的环境保护政策，阐述了几种基于静电测量原理的大气中粉尘主要排放源——工业烟道中固体颗粒物质量排放量的在线自动连续监测方法。给出了这些方法的原理，系统构成及它们的使用特点。     

Problems of Locating Acoustic Emission Sources

Russian Journal of Nondestructive Testing - The accuracy of locating acoustic emission (AE) sources in the zones of stress raisers (central holes 5 mm in diameter) located a distance of 40 mm away...     

声发射技术在设备故障诊断中的应用

信号采集是机械设备故障诊断的基础,信号采集得是否及时、正确直接影响到诊断结果的正确性。利用声发射技术实现故障信息的实时采集,同时使用计算机对信息分析、处理,以此为原理构成了在线故障诊断监测系统。本文对这一系统进行了简要介绍。     

机械零件的声发射检测技术

主要从声发射机理、声发射传感器的研究和多传感器检测技术三个方面介绍了机械零件声发射检测技术的特点、研究现状和发展趋势。     

材料磁声发射技术研究

对几种常用钢材的磁声发射（ＭＡＥ）特性进行了测试,研究了材料的化学成分、显微组织及应力状态对材料磁声发射的影响,从而进一步证实,磁声发射技术作为无损检测材料的一种新方法是可行的。