大型回转件自动超声波探伤轨迹规划及仿真分析

针对目前大型回转件主要依靠传统手工探伤的种种缺陷,开展了自动化超声波探伤的轨迹规划与探伤系统运动规律的研究,并进行探头扫查轨迹运动仿真。阐述了自动化探伤模拟手工探伤的工艺原理,分析了工件、探头的运动规律,规划了探头扫查轨迹,整个自动化探伤工艺符合无损探伤国家标准,并将探伤效率提高了5.46倍;联合MATLAB和ADAMS软件对探头扫查轨迹进行仿真,仿真结果验证了轨迹规划的正确性。     

Detection of cracks under threads of studs of power equipment and drill pipes during ultrasonic testing

Special features of finding cracks under threads of drill pipes and studs of power equipment are considered. Standard angle single-crystal probes, a special normal dual probe, and a probe of head waves were used for ultrasonic testing. They were compared and their efficiency was estimated. The succession of tuning of the scan duration, the depth gage, and the sensitivity of the probe is described.     

A method for the determination of the volumes of arbitrarily-spaced local defects during eddy-current testing of cylindrical items by a multi-unit probe

The design of a data-analysis algorithm in the eddy-current testing of cylindrical items by a multi-unit probe, which allows the automatic determination of the volume of local defects between single probes that are included in a multi-unit probe, has been described. The effectiveness of the algorithm is confirmed by its repeatability studies.     

曲面形工件的双探头超声寻位检测方法

针对难以一次定位的曲面形工件的超声检测，提出了一种双探头超声寻位检测方法。对涉及的一些问题给出了可行的解决办法。开发了相应的检测软件，并进行了仿真实验。理论分析与仿真结果表明，该方法是切实可行的。     

提高触发式测头在机检测精度

在机检测是保证数控机床加工精度的有效手段。文章系统介绍了触发式测头测量系统的特点及其误差组成，阐述了对在机检测系统及其测量误差修正的技术，最后以实例说明了尺寸误差的反馈补偿的效果。     

电磁超声电声转换效率的影响因素分析

电磁超声是一种非接触超声检测方法,因不需要耦合剂,在一些常规超声无法实施的特殊检测领域发挥着重要作用。但是,由于电磁超声电声转换效率低,制约着电磁超声的广泛应用。分析了几种参数对电磁超声电声转换效率的影响,包括探头的提离、激励信号的电流幅值、频率、周期个数和仪器的输出功率等几个因素。研究表明：随着探头提离的增大,电磁超声的信号几乎成指数衰减;通过优化激励信号的电流幅值、周期个数和激励频率以及在探头两端增加阻抗匹配单元,可以提高电磁超声的电声转换效率。     

CNC齿轮测量中心上盘形凸轮测量方法研究

研究了直接在CNC齿轮测量中心上检测凸轮并评定误差的方法和理论。在凸轮工件型面上直接采集测量数据,用三次样条插值函数拟合测头中心轨迹,通过测头半径补偿和凸轮从动轮数据转换,得到凸轮升程曲线,运用最小条件法评价凸轮升程误差。此方法具有测量过程简便、测量效率高、计算精度高、应用性广等优点,适用于以CNC齿轮测量中心为检测设备的自动加工系统。     

Electromagnetic devices for assessment of the state of reinforcement elements in reinforced-concrete structures

Functional capacities of a unidirectional eddy-current probe are studied from the viewpoint of localization of reinforcement in reinforced-concrete elements and measurement of its geometric parameters. Such a design of the probe is shown to be inefficient for testing reinforced-concrete items where the reinforcing frame is complex in shape and the content of reinforcement is over 2%. A design of the attachable eddy-current probe is proposed that allows this problem to be solved more efficiently.     

坐标测量机上盘状凸轮检测方法研究

本文研究直接在三坐标测量机上检测凸轮并评定误差的方法和理论。在凸轮工件型面上接采点测量数据,用不等距三次Ｂ样条函数和最小二乘法拟合测头中心轨迹,通过测头半径补偿和凸轮从动轮数据转换,得到凸轮升程曲线,运用最小条件法评价凸轮误差,同时还可以评价凸轮机的速度、加速误差。数字仿真计算和实验结果表明,本文方法具有测量过程简便,测量效率高、计算精度高,应用性广播等优点,适用于三坐标测量机为检测设备的自动加工     

大规模MCM基板互连探针测试和路径优化

已有的路径优化算法在MCM基板互连测试中已经发挥了一定的作用，但由于MCM的高密互连特性，使得测试变得更加复杂和困难，因此人们希望能引入新的方法与思路，以解决MCM基板互连测试的路径优化问题。将蚁群算法应用到互连测试探针路径优化问题当中，根据MCM基板互连测试的特点，建立探针路径优化的模型。提出一种针对大规模MCM基板互连探针测试的方法，首先将MCM基板进行分片，然后对每片进行优化，最后将优化结果连接在一起，成为一条完整的路径。实验结果表明，蚁群算法能在较短的时间内得到更优的路径。     

双机械手操作的轴承阵列漏磁检测方法与系统

为满足对轴承套圈更快捷、更全面、更精细的自动化无损检测需求,提出了一种基于交直流复合磁化的漏磁检测方法。通过布置正交的交流、直流磁化器对套圈的检测面进行复合磁化,可以激励出不同方向裂纹的漏磁场,再通过设计的差分电感仿形阵列探头检测复合磁化下漏磁场的法向分量,通过分频处理分别得到周向和轴向的裂纹信号。在自动化检测过程中,双机械手在2个不同工位分别带动漏磁检测探头,通过快速精准的跟踪扫查运动实现对轴承套圈内、外径面及2个端面的全方位自动化探伤。试验表明,该系统的定位精度满足轴承套圈的检测需求,而且开放式可编程的结构有利于轴承生产中的快速换型。     

Heterodyning based portable instrument for eddy currents non-destructive testing

The development and implementation of a portable eddy currents testing instrument with heterodyning based measurements is presented in this paper. The instrument is composed by a dedicated electronic measurement circuitry embedded inside a rugged tablet computer for control and visualization and that interfaces a small footprint planar eddy currents probe. A DDS waveform generator and a transconductance amplifier are used to drive the probe current. The probe output voltage is amplified up to 60 dB and down-converted to an intermediary frequency, which is then digitized. IQ demodulation of the digitized signal is used to obtain the real and imaginary components of the probe output and is computed in real time by the embedded digital signal processor and transmitted to the host computer by USB. The eddy currents testing instrument can be operated as a battery powered standalone device with post-processing and visualization capabilities which can be modified for specific applications without the need for hardware modifications. The system architecture, electrical characterization of the analog circuit, digital signal processing and visualization interface are described. The eddy currents inspection results of an aluminum sample with synthetic defects and friction stir welding joint samples, using this instrument are presented.     

多层厚度电涡流检测技术及实验研究

研究了多层厚度的电涡流检测原理和有限截面线圈置于多层结构上其各种参数与阻抗变化关系的数学模型；建立了用于多层厚度检测的涡流检测系统，对两层厚度的检测进行了几种检测电压值--厚度回归模型实验研究，并对反演计算结果进行了比较分析，给出了最佳的拟合模型和多层厚度反演算法。     

Comparative evaluation of coil and hall probes in hole detection and thickness measurement on aluminum plates using eddy current testing

The design, test, and comparison of one coil probe and one Hall probe using eddy current testing in the field of non-destructive evaluation is presented. Real tests were performed using alumi- num plates. This research concludes that (1) both probes provided broadband frequency responses up to 1000 KHz, which are wide enough for the most common applications; (2) the coil probe provided higher signal to noise ratio (SNR) than the Hall probe; (3) both probes detected the four holes success- fully and provided enough sensitivity to classify them by diameter; and (4) the coil probe provided higher accuracy than the Hall probe when measuring thickness lower than 1 mm, and lower accuracy when measuring thickness higher than 1.5 mm.     

InSb磁敏电阻脉冲涡流传感器的研究

脉冲涡流检测方法是涡流检测技术的一个新兴分支。因脉冲信号频带很宽,比单一频率正弦涡流衰减慢,其瞬态感应电压信号中就包含了有关缺陷的重要信息。本文分析了InSb磁敏电阻作为脉冲涡流检测元件的工作原理,设计了探头结构和调理电路,有效抑制了环境温度的干扰,并分析了应用InSb磁敏电阻的涡流探头检测金属裂纹特征的信息提取方法。实验结果表明,采用InSb磁敏电阻作为脉冲涡流检测传感器,具有较高的裂纹灵敏度,且可以较好地反映裂纹的深度。     

中子谱仪样品台几何误差建模和灵敏度分析

介绍了中子衍射残余应力测试谱仪样品台的结构和基于标准探针的定位测量方法;利用多体运动学和齐次变换矩阵建立了基于标准探针定位测量方法的样品台定位误差模型;最后分别对模型中涉及的42个误差分量进行了定位误差的灵敏度分析。分析结果对中子衍射残余应力测试谱仪样品台的精度设计具有参考作用。     

Investigation of the magnetic field response from eddy current inspection of defects

Eddy current testing is one of the most widely used methods in non-destructive testing for the inspection of conductive materials. Numerical modelling of eddy current testing has emerged as an important approach alongside experimental studies. This paper investigates an application of numerical modelling and experimental study as a means of the quantitative non-destructive evaluation (QNDE) of defects in conductive samples. There are two methods of measuring eddy current response, more commonly by measuring the change in impedance of the eddy current probe coil, or as used in this work, by measuring the change in magnetic field directly using magnetic field sensors such as superconducting quantum interference devices, giant magneto resistance, or as in this case Hall sensors. Specifically, measurements made using an eddy current probe containing an excitation coil and a Hall sensor, experimentally obtained using an X?CY scanner table, are compared with a numerical (finite element method) model. The discrepancies between the experimental tests and the numerical models have been analysed and explained, which is an important factor in engineering applications of QNDE.     

Measuring the asymmetry of the longitudinal charge distribution in an electron bunch on the ВЭПП-4М collider

A method for measuring the asymmetry of the longitudinal charge distribution in an electron bunch of the ВЭПП-4М collider by an electron beam probe is proposed. The operating principle of the electron beam probe and the measuring technique are described. Interaction between the testing beam and an asymmetric relativistic bunch is simulated, and the asymmetry of the electron bunch on the ВЭПП-4 collider is measured. The main components of the error in measuring the asymmetry are determined.     

Experimental and theoretical investigation of needle contact behavior of wafer level probing

Wafer probing technique is important for testing integrated circuit devices. For the safety of measured chips, the probe card must be examined to verify the performance before online testing as it must avoid the defect of the pad edge excursion and the excessive scrub length. In addition, during wafer testing the oxidized layer of pad has to be pierced to gain the stable testing by the needle, which should have sufficient force. Therefore, a well-designed probing system is significantly important for wafer testing. In this paper, the simple and accurate theoretical method is established, which benefits to design an appropriate probing system rapidly. Moreover, the finite element method is also developed for analyzing the contact behavior between the needle and the aluminum pad during wafer testing. The results, which are determined by using the theoretical analysis, the finite element method and the experiment, are consistent. Finally, the parameters of a well-designed probing system for testing smaller chips are investigated.