Ternopil Ivan Pul'uj National Technical University

About: Ternopil Ivan Pul'uj National Technical University is a based out in . It is known for research contribution in the topics: Deformation (engineering) & Fracture toughness. The organization has 134 authors who have published 187 publications receiving 1019 citations.

Mechanical Characteristics and Wear Resistance of the Cladding Layers Obtained by Melting of Cored Wires with Simultaneous Vibration of Substrate

Abstract: Abstract A wear proof layer was obtained by applying vibration with a frequency of 100 Hz and amplitude of 0; 70; 300 μm to the cored wire of Fe-Cr-B-C doping system during welding. It was shown that horizontal vibration affects the grinding process of boride inclusions: their average diameter reduces from 175 to 5 μm, and the amount of (FeCr)2B plastic phases increases during the redistribution of phases. Wear resistance of the metal, which was deposited using horizontal vibration with an amplitude of 300 μm, increases by 2.3-2.5 times due to wear with the fixed and unfixed abrasive material, and by 2.8 times due to wear under impact loads. For restoration and strengthening of large-size parts, it is proposed to add Al-Mg powder (Al = 47 - 53 %, Mg = 53-47% wt. %) to the CW charge to increase wear resistance of the deposited metal of the Fe-Cr-B-C system. This contributes to the dispersion of the boride inclusions, the average diameter of which decreases from 70 to 5 μm. In the structure of the deposited metal of the Fe-Cr-B-C system, inclusions of the complex alloyed nitrides are extricated with an average size less than 1.0 μm. As a result, the average value of microhardness increases from 700 to 900 HV. Wear resistance of the deposited metal increases by 1.5 times due to wear with the fixed and unfixed abrasive material, and by 2.0 times due to wear under impact loads.

Deformation and energy parameters of fracture of steel of the main gas pipeline

Abstract: By example of steel 17G1S, the regularities in the impact fracture of Charpy specimens at normal and low temperatures are described. The relationship between the energy parameters of fracture (impact toughness) and the deformation response of the material (the height of shear lips) of the specimens from the pipe steel is established. The micromechanisms of impact fracture of the material are described. At 20 °C and –30 °C, focal splitting of the material was observed on the fracture surface of specimens; at –60 °C, the material failed in a brittle manner by the mechanism of cleavage.

Statistical Analysis of Human Heart Rhythm with Increased Informativeness

Abstract: Abstract The new methods of statistical analysis of heart rhythm were developed based on its generalized mathematical model in a form of random rhythm function, that allows to increase the informativeness and detailed analysis of heart rhythm in cardiovascular information systems. Three information criteria (BIC, AIC and AICc) were used to determine the cumulative distribution functions that best describe the sample and to assess the unknown parameters of distributions. The usage of the rhythm function to analyse heart rhythm allows to consider much better its time structure that is the basis to improve the accuracy of diagnosis of cardiac rhythm.

The evaluation of durability of structural elements using neural networks

Abstract: While in operation structural elements may have cracks, which usually grow up to critical size due to further cyclic loading, so that the component is likely to be destroyed. Therefore, it is important to study the process of fatigue failure of structural materials. The aim of this work was to evaluate the durability of structural elements during their design phase, taking into account the achieved level of material damage, and to predict the fatigue crack growth (FCG) rate in an aluminium D16chT alloy under regular loading using neural network (NN). Based on experimental data of FCG at stress ratio R = 0, FCG rate was predicted in this alloy. The results obtained by the authors are in good agreement with the experimental data.