A permanent-magnet-based attached instrument used to inspect articles on the basis of their coercive force

An attached magnetic instrument that uses two permanent magnets to magnetize and demagnetize an article is considered. When one of the magnets is set at a fixed angle, the rotation angle of the other magnet is proportional to the coercive force of an article and is used as the tested parameter.     

On new possibilities for making local measurements of the coercive force of ferromagnetic objects

The possibility of reducing the influence of both the gap in a transducer-object combined circuit and the shape of tested objects on the results of local measurements of their coercive force is investigated. It is shown that additional measurements of the maximum magnetic flux in the circuit and the tangential component of the magnetic field on the surface of the tested area of the object, which is retained after the magnetizing current is turned off, allow a substantial decrease in the corresponding errors.     

Calculation of the induction of a constant magnetic field created in a ferromagnet by an attachable electromagnet

On the grounds of the numerical calculation of the induction of a magnetic field excited in a ferromagnet by scanners in the form of Π-shaped and solenoidal electromagnets, it is established that the Π-shaped type provides a deeper penetration of a magnetic field into a ferromagnet and its better localization in a specified volume. The induction of a magnetic field appearing under the action of a Π-shaped scanner in a ferromagnet decreased with an increase in both the thicknesses of the ferromagnet and the gap between the magnetic conductor of a scanner and the surface of a material and also depended slightly on changes in its width; a maximal scanner winding current exists, above which the induction of a magnetic field in a material changes slightly.     

Distribution of the induction of a quasi-stationary magnetic field created in a ferromagnet by an attachable electromagnet

As a result of numerical calculations, the spatial and time distributions of the induction of a quasi-stationary magnetic field, which was created in a studied ferromagnet by U-shaped and solenoidal attachable electromagnets (AEMs) at frequencies of 1 and 10 Hz, were obtained. The presence of a phase shift between the amplitude values of the magnetic-field induction at different depths in the specimen, which increases with the frequency of the exciting current, was revealed. The dependences of the magnetic-field penetration depth into the ferromagnet on the magnetic reversal frequency were studied. It was found that for the frequency range under study the magnetic-field penetration depth for both types of AEM is smaller than that for the corresponding stationary case.     

大坝安全监测网络传感器通用数据采集模块设计

介绍了一种基于微处理器ADuC812和通信接口芯片SN65LBC184的大坝安全监测网络传感器通用数据采集模块。通用数据采集模块与现有大坝安全监测传感器相结合。可构成适合于大坝安全监测的网络传感器,从而为实现大坝安全监测网络化打下良好的基础。     

Using a corrected least-squares procedure and accounting for structural parameters when analyzing the correlation between the impact strength of low-alloyed steels and their coercive force

The use of a corrected least-squares procedure that takes the error of impact-strength estimation into account, as well as several structure parameters, such as the equiaxial grain size number, Widmanstätten ferrite grain size number, and bainite percentage, allowed us to substantially improve the constraint equations between the impact strength and coercive force for a group of specimens. These specimens were sampled from no. 60 flange beams made of 09Г2 steel and exhibited no preliminary correlation between these parameters.     

An analytical method for the process capability of a precision component of an instrument

The precision and accuracy properties of optics affect the measuring, projection and scanning efficiency of optical instruments tremendously. Consequently, the optical centre of optical glass is an important test item in the quality control of optical glass. To effectively check the concentration of optical glass, the evaluation tools require high accuracy and precision. However, the existing evaluation tools, which use numerical measurements to check the quality of optical glass, are not objective enough to attain accuracy. As a result, the test results may be rendered unreliable. Thus, an evaluation method for process capability and performance is quoted here to define the indices for the precision degree (E_p) and the accuracy degree (E_a). Then, the principle of statistics is used to derive unbiased estimators of these indices. These equations can be used to objectively judge the precision, accuracy degree and applicability of measure the optical centre of optical glass.     

The effect of a gap between the poles of an attachable electromagnet and a tested component on coercimeter readings and methods for decreasing it (Review)

The main drawback of a coercimeter with attachable electromagnets (AEM) is its sensitivity to a random gap between electromagnet poles and a tested article formed in the process of inspection. The causes of such sensitivity are analyzed and the methods for decreasing it are considered.     

交变磁场作用下等离子弧热通量的研究

为了扩大等离子弧在金属加工领域中的应用范围,提高被加工金属的加工质量,提出用交变的磁场作用于转移型的等离子弧。在交变的电磁力作用下,等离子弧在被加热的金属表面上振荡,从而扩大了被加热金属表面的加热面积。施加的磁场强度可控制离子弧振荡运动的振幅。过强的磁场强度使等离子弧的振荡是不稳定的。实验表明,包围等离子弧的中性气体流相当大的影响热通量。研究得出,在弱磁场中,等离子弧运动的振幅是与施加的磁通量密度成正比,到阳极上的总热流量不受外加的磁场影响。     

Development and certification of the MAΓEOC calibration block for magnetic properties of a pipeline with local heterogeneities

Some general features of metrological supplementation for techniques and means of nondestructive testing of materials and articles are discussed. In particular, the CO MAГEOC calibration block for magnetic properties of a pipeline with local inhomogeneities that was developed and certified at CПEKTP, in cooperation with the Ural Research Institute of Metrology (ФГУП УНИИМ), is considered.     

Study of the nanoscopic deformation of an annealed nafion film by using atomic force microscopy and a patterned substrate

We demonstrated the repetitive imaging of the same area of a nafion film before and after annealing by using atomic force microscopy (AFM). In order to find the exact same area of the same sample after changing the cantilever and reattaching the sample, a micropatterned substrate was developed. A micropattern with a 250–500 μm pitch was prepared on the backside of a transparent glass substrate. This pattern includes various signs such as colored letters and numbers at the center of each lattice of the pattern. The nanostructures fabricated by AFM nanolithography on a nafion film using this new method were successfully characterized before and after annealing (over 100 °C). The AFM images clearly showed that the nanostructures on a nafion film were dramatically changed by annealing. The data indicated an evidence to understand why the nafion fuel cell does not work well at high temperatures. Our method is probably effective for the study of nanoscopic dynamics in various surface structures.     

Study of an internal magnetic abrasive finishing using a pole rotation system: Discussion of the characteristic abrasive behavior

An internal magnetic abrasive finishing process using a pole rotation system was proposed to produce highly finished inner surfaces of workpieces used in critical applications. Previous research found that the process incorporating one of the characteristic behaviors of the abrasive, the jumbling of the abrasive, results in aggressive contact of the abrasive against the inner surface, disturbing the smooth surface finish. The aim of this paper, therefore, is to characterize the in-process abrasive behavior against the surface and its effects on the finishing characteristics and to describe the finishing mechanism. The magnetic force acting on the magnetic abrasive, controlled by the field at the finishing area, is considered the primary influence on the abrasive behavior against the inner surface of the workpiece. This study examines the relationships between the magnetic field, the force on the abrasive, and the abrasive behavior. The surface roughness and material removal measurements resulting from finishing experiments demonstrate the effects of the abrasive behavior on the surface modifications. This paper also proposes a method to monitor the in-process abrasive behavior to facilitate processing.     

Use of a magnetic method for estimating the deformation stability of retained austenite in sheet high-strength economically alloyed steels used in the automotive industry

A comparative analysis of a magnetic method and X-ray diffraction analysis used for estimating the volume fraction of retained austenite in a sheet high-strength economically alloyed steel (applied in the automotive industry), which was subjected to uniaxial tension at different temperatures (+20)–(?40°C) until the onset of the strain-hardening stage, is performed. At a low austenite content (<5–8 vol %), the advantage of the magnetic method for estimating the deformation stability of austenite in these steels is shown.     

信号输入通道的逆向建模及其在提高智能仪表测量精度中的应用

本文采用时变系数多项式即静态非线性函数对信号输入通道进行逆向建模。借此模型 ,克服零点漂移及增益漂移对检测精度的影响 ,补偿信号输入通道的非线性 ,实现了数据的规范化处理。将此模型用于数字控制器的设计 ,取得了预期的效果。     

Study on the dynamic interaction of multiple clearance joints for flap actuation system with a modified contact force model

Journal of Mechanical Science and Technology - To analyze the effects of clearance joint number and dynamic interaction on responses of the flap actuation system, a dynamic analysis model is...     

一种管内壁自动清淤器磁转子的特性

物料传输管道的结垢一直是有色冶金行业突出的问题，影响了生产工艺要求和生产过程的自动检测。采用非接触的磁力驱动技术能实现对关键管路内壁进行高效螺旋清洗。围绕研制的一种新型自动清淤器，以设计出一种高性能磁力驱动转子为目标，对内外磁转子结构参数进行了优化，并以磁场的有限元分析为基础对磁转子的磁路、转矩和耦合机理等特性进行分析，为自动清淤器设计提供理论依据。     

Study of a simulator database and an experiment for the evaluation of highway driving safety

Drivers acquire more than 90% of visual information through road signs. However, the road signage along highways can cause driver discomfort and traffic accidents. Conducting experiments along a real highway may cause traffic accidents; therefore, obtaining accurate results from such experiments is difficult. Consequently, this paper reports an experiment for evaluating highway driving safety to reduce the causes of accidents through highway design. It examines the development of a highway database to classify road types in exact accordance with real highways. The study involves an experiment using a driving simulator. The highway database was constructed in two aspects (original and alternative designs) compatible with the DirectX program of Multigen. Four types of physiological measurements (i.e., electrocardiogram, electromyography, electrooculography, and galvanic skin response) were taken from 33 subjects using Biopac equipment in the developed highway database. The skin temperature was measured by a thermal camera. The driver’s state was measured through the Subjective Workload Analysis Technique, NASA-Task Load Index, and Modified Cooper-Harper, among various psychological methods. Statistical analysis was conducted to assure the reliability of the results using the Statistical Package for the Social Sciences 12.0 program.     

The use of an ultrasonic flaw detector with a phased antenna array for the recording of echo signals to reconstruct the images of reflectors by the method of projection in the spectral space

A method of automated ultrasonic testing based on the use of a PAA flaw detector for the recording of echo signals followed by the reconstruction of the image of reflectors by applying the 3D variant of the method of projection in the spectral space (3D-PSS) is considered. Customized setting of the PAA flaw detector makes it possible to simulate the operation of many single-element transducers with different angles of incidence. This approach allows one to obtain the images of reflectors with a high resolution and a high signal-to-noise ratio at a depth of more than 100 mm. A procedure for the calibration of an antenna array on a prism operating in the mode of emulation of several piezoelectric transducers with different angles of incidence is discussed. The results of a testing a fragment of the support billet for the ITER diverter when obtaining the images by the classical PAA method and with the use of 3D processing, which demonstrate the efficiency of the developed testing technology, are presented.