Papers by Author: Roman Szewczyk

Abstract: The application of magnetic-property oriented methods for non-destructive testing is very promising due to its low cost and robustness. This paper presents the methodology of simulating the magnetic properties of martensitic X30Cr13 steel applying the extended Jiles-Atherton model. On the basis of experimental measurements, the parameters of the Jiles-Atherton model were determined by an evolutionary strategy together with gradient optimisation. A very good agreement between experimental hysteresis loops and the model was confirmed by a high value of determination coefficient. The presented results open new possibilities of developing methods for non-destructive testing of energetic turbines made of X30Cr13 stainless steel. Moreover, quantitative simulation gives a possibility of a better understanding of magnetisation processes.

Abstract: This paper concerns the possibility of use of the Jiles-Atherton-Sablik extended model to describe the magnetic characteristics for construction steel ST3. Result of the modelling utilizing extended Jiles-Atherton-Sablik model are in good agreement with results of experimental measurements for magnetic hysteresis loops B(H). However experimental results indicated, that the influence of temperature on B(H) characteristics is relatively small and can be neglected from the point of view of modelling for technical applications, such as stress estimation for non-destructive testing.

Abstract: Paper discusses the possible of application of iron-based amorphous Fe₇₇Cr₂B₁₆Si₅ alloys for tensile force sensors. In proposed sensor uniform stresses were generated in direction of the ribbon ring core axis. As a result stresses were perpendicular to the magnetizing field direction, what increases sensor sensitivity as well as simplified analyses. The results show high magnetoelastic sensitivity of Fe₇₇Cr₂B₁₆Si₅ amorphous alloy. Moreover, this magnetoelastic sensitivity increases during the annealing process, which is connected with thermal relaxation of amorphous alloy.

Abstract: Paper presents a novel application of magnetostrictive delay lines, which give a possibility of real time monitoring of strain in ceramic components. Magnetostrictive delay line was based on highly magnetostrictive Fe-Si-B amorphous alloy ribbon, mounted outside of ceramic component, what is a new solution for increasing sensor’s sensitivity. Developed specially for this sensor, hybrid digital-analog signal processing unit covers the sample-and-hold integrated circuit. The achived sensitivity and repeatability of the sensor confirms, that such solution is suitable for ceramic machine tool monitoring.

Abstract: Paper presents the results of investigation on functional characteristics of magnetoelastic compressive force sensor utilizing two Fe81Si4B15 amorphous alloy ring-shaped cores. Uniform distribution of stresses in one of two cores was achieved owing to special non-magnetic backings. Signal from sensing coils of cores was connected to differential amplifier, whereas sine wave voltage signal was applied to magnetizing circuit. High stress sensitivity of developed sensor was indicated together with expected reduction of temperature sensitivity of magnetoelastic sensor. These results confirm, that differential configuration of magnetoelastic sensor is suitable for practical application in sensors development.

Abstract: The paper presents a new idea of extension of the Jiles-Atherton-Sablik model for modeling of the influence of mechanical stresses on magnetic hysteresis loops of amorphous alloys. In the extended model changes of parameter k are considered during the magnetization and the influence of stresses on eight parameters of the Jiles-Atherton-Sablik model is taken into account. Verification of the model was carried out on the base of experimental results obtained for Fe40Ni38Mo4B18 amorphous alloy subjected to both stress from external compressive force as well as shearing stresses from torque. In the experiment uniform stress distribution was achieved in both cases due to special mechanical system of backings. Evolutionary strategies were used in conjunction with gradient optimization for calculation of the model parameters. Results of simulation are in good agreement with experimental findings. As a result the extended Jiles- Atherton-Sablik model enables modeling of the magnetoelastic characteristics of amorphous materials for mechatronic inductive components such as compressive stress and torque sensors.