Finite Element Modeling of the Bulk Magnetization of Railroad Wheels to Improve Test Conditions for Magnetoacoustic Residual Stress Measurements

The magnetoacoustic measurement technique has been used successfully for residual stress measurements in laboratory samples[l-4]. However, when used to field test samples with complex geometries, such as railroad wheels, the sensitivity of the method declines dramatically[5,6]. It has been suggested that the decrease in performance may be due, in part, to an insufficient or nonuniform magnetic induction in the test sample[6]. The purpose of this paper is to optimize the test conditions by using finite element modeling to predict the distribution of the induced bulk magnetization of railroad wheels. The results suggest that it is possible to obtain a sufficiently large and uniform bulk magnetization by altering the shape of the electromagnet used in the tests. Consequently, problems associated with bulk magnetization can be overcome, and should not prohibit the magnetoacoustic technique from being used to make residual stress measurements in railroad wheels

Correlation Between NDE Measurements and Physical Properties of Copper Powder Metallurgy Components

Square D, a world leader in the manufacturing of electrical components and systems, needed to insure it was using only high quality powdered metal (PM) components in one of its ’ line of circuit breakers products. Low strength powdered metal components had been detected by routine destructive testing practices which subsequently rejected entire lots of product. Although the occurrence of a failure was infrequent, Square D felt that improvements in both the design of the part and method of inspection could be implemented. As a result, the part design was improved which made all of the parts acceptable all of the time with respect to break strength level. Square D was still troubled by the fact that, even though all of the parts were now acceptable, there was still a very low percentage of parts that exhibited lower than average strength

Detection of Expended Fatigue Life of AISI 4140 Steels from Magnetic Measurements

The objective of this study was to determine how magnetic properties such as coercivity, hysteresis loss and initial susceptibility of AISI 4140 steels depended on the expended fatigue life. If one or more of these magnetic properties was found to be sensitive to fatigue cycling, then it should be possible to devise a magnetic NDE technique based on these results, for monitoring of in-service components subjected to fatigue cycling

Linearized MFL Model for Embedded Flaw Detection in Rails

Numerical models simulating magnetic flux leakage (MFL) phenomenon in ferromagnetic materials are nonlinear in nature and hence require excessive computational effort. This paper describes an approach for developing an equivalent linear model (ELM) where the ferromagnetic region is appropriately partitioned into different domains with each domain being assigned a constant permeability value depending on the magnetization level and the flaw size. The nonlinear behavior of the multi-layered object is then modeled using a linearized MFL model. The model is first validated and then applied to the flaw detection problem in a rail geometry.</p

Theorising age and generation in development: A relational approach

This introduction outlines the analytical approach informing the articles presented in this special issue. The project of ‘generationing’ development involves re-thinking development as distinctly generational in its dynamics. For this, we adopt a relational approach to the study of young people in development, which overcomes the limitations inherent to common categorising approaches. Concepts of age and generation are employed to conceptualise young people as social actors and life phases such as childhood and youth in relational terms. Acknowledging the centrality of young people in social reproduction puts them at the heart of development studies and leads the articles comprising this special issue to explore how young people’s agency shapes and is shaped by the changing terms of social reproduction brought about by development

Social factors influencing Russian male alcohol use over the life course: a qualitative study investigating age based social norms, masculinity, and workplace context

The massive fluctuations occurring in Russian alcohol-related mortality since the mid-1980s cannot be seen outside of the context of great social and economic change. There is a dearth of qualitative studies about Russian male drinking and especially needed are those that address social processes and individual changes in drinking. Conducted as part of a longitudinal study on men’s alcohol consumption in Izhevsk, this qualitative study uses 25 semi-structured biographical interviews with men aged 33–60 years to explore life course variation in drinking. The dominant pattern was decreasing binge and frequent drinking as men reached middle age which was precipitated by family building, reductions in drinking with work colleagues, and health concerns. A minority of men described chaotic drinking histories with periods of abstinence and heavy drinking. The results highlight the importance of the blue-collar work environment for conditioning male heavy drinking in young adulthood through a variety of social, normative and structural mechanisms. Post-Soviet changes had a structural influence on the propensity for workplace drinking but the important social function of male drinking sessions remained. Bonding with workmates through heavy drinking was seen as an unavoidable and essential part of young men’s social life. With age peer pressure to drink decreased and the need to perform the role of responsible breadwinner put different behavioural demands on men. For some resisting social pressure to drink became an important site of self-determination and a mark of masculine maturity. Over the lifetime the place where masculine identity was asserted shifted from the workplace to the home, which commonly resulted in a reduction in drinking. We contribute to existing theories of Russian male drinking by showing that the performance of age-related social roles influences Russian men’s drinking patterns, drinking contexts and their attitudes. Further research should be conducted investigating drinking trajectories in Russian men

Correlation Between NDE Measurements and Physical Properties of Copper Powder Metallurgy Components

Square D, a world leader in the manufacturing of electrical components and systems, needed to insure it was using only high quality powdered metal (PM) components in one of its ’ line of circuit breakers products. Low strength powdered metal components had been detected by routine destructive testing practices which subsequently rejected entire lots of product. Although the occurrence of a failure was infrequent, Square D felt that improvements in both the design of the part and method of inspection could be implemented. As a result, the part design was improved which made all of the parts acceptable all of the time with respect to break strength level. Square D was still troubled by the fact that, even though all of the parts were now acceptable, there was still a very low percentage of parts that exhibited lower than average strength.</p

An identification procedure of electromagnetic parameters for an induction motor equivalent circuit including rotor deep bar effect

The paper presents an identification procedure of electromagnetic parameters for an induction motor equivalent circuit including rotor deep bar effect. The presented procedure employs information obtained from measurement realised under the load curve test, described in the standard PN-EN 60034-28: 2013. In the article, the selected impedance frequency characteristics of the tested induction machines derived from measurement have been compared with the corresponding characteristics calculated with the use of the adopted equivalent circuit with electromagnetic parameters determined according to the presented procedure. Furthermore, the characteristics computed on the basis of the classical machine T-type equivalent circuit, whose electromagnetic parameters had been identified in line with the chosen methodologies reported in the standards PN-EN 60034-28: 2013 and IEEE Std 112TM-2004, have been included in the comparative analysis as well. Additional verification of correctness of identified electromagnetic parameters has been realised through comparison of the steady-state power factor-slip and torque-slip characteristics determined experimentally and through the machine operation simulations carried out with the use of the considered equivalent circuits. The studies concerning induction motors with two types of rotor construction – a conventional single cage rotor and a solid rotor manufactured from magnetic material – have been presented in the paper

VQZ-plasty for Mitrofanoff and Malone stoma

мочевого пузыря болезни, мочи недержание, операция Митрофанова, операция Малона, дет