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1

Evaluation of stress-strain state of vehicles’ metal structures elements

Hrevtsev O., Selivanova N., Popovych P., Poberezhny L., Rudyak Yu., Shevchuk O., Poberezhna L., Ivanova A., Skyba O., Shashkevych O., Hrytsanchuk A.

Archives of Materials Science and Engineering

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2022

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Vol. 113, nr 2

77--85

EN

Purpose: Develop a method for determining and evaluating the stress-strain state, in particular the distribution of thermomechanical stresses in the materials of individual rotating parts of vehicles. Design/methodology/approach: The proposed method is based on the principle of gradual approximations of the solution when the boundary conditions are satisfied on the curvilinear limiting surfaces of the disk body. Findings: The proposed method of determining and estimating the distribution of thermomechanical stresses in the disk material makes it possible to take into account the variable geometry: thickness and presence of a hole in the central part of the disk, also correctly determine stress strain state at any point of unevenly heated rotating axial body. Research limitations/implications: The work uses generally accepted assumptions and limitations for thermomechanical calculations. Originality/value: It is proved that in real disks the stress-strain state is spatial, and the well-known method based on the hypotheses of the plane-stress state does not provide the possibility of calculating the values of stresses in the thickness of the disk. The obtained results can be used as a basis for improving the methodology of auto technical examination of road accidents. In addition, they can be taken into account by design engineers of car brake systems.

2

The Effect of Different Mn/Fe Ratio on Microstructure Alloy Based on Al-Si-Mg

Bolibruchova D., Ivanova A.

Archives of Foundry Engineering

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2019

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iss. 3

15--20

EN

This article deals with the effect of manganese that is the most applied element to eliminate the negative effect of iron in the investigated alloy AlSi7Mg0.3. In this time are several methods that are used for elimination harmful effect of iron. The most used method is elimination by applying the additive elements, so-called iron correctors. The influence of manganese on the morphology of excluded iron-based intermetallic phases was analysed at various iron contents (0.4; 0.8 and 1.2 wt. %). The effect of manganese was assessed in additions of 0.1; 0.2; 0.4 and 0.6 wt. % Mn. The morphology of iron intermetallic phases was assessed using electron microscopy (SEM) and EDX analysis. The increase of iron content in investigated alloys caused the formation of more intermetallic phases and this effect has been more significant with higher concentrations of manganese. The measurements carried out also showed that alloys with the same Mn/Fe ratio can manifest different structures and characteristics of excluded iron-based intermetallic phases, which might, at the same time, be related to different resulting mechanical properties.

3

Modeling of Heat Engineering Parameters of Casting and Rolling Complexes Work

Biryukov A., Ivanova A.

Archives of Foundry Engineering

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2019

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iss. 3

11--14

EN

The paper consists the problem of developing a scientific toolkit allowing to predict the thermal state of the ingot during its formation in all elements of the casting and rolling complex, between the crystallizer of the continuous casting machine and exit from the furnace. As the toolkit for the decision making task the predictive mathematical model of the ingot temperature field is proposed. Displacement between the various elements of the CRC is accounted for by changing the boundary conditions. Mass-average enthalpy is proposed as a characteristic of ingot cross-section temperature state. The next methods of solving a number of important problems with the use of medium mass enthalpy are developed: determination of the necessary heat capacity of ingots after the continuous casting machine for direct rolling without heating; determination of the rational time of alignment of the temperature field of ingots having sufficient heat capacity for rolling after casting; determination of the total amount of heat (heat capacity) required to supply the metal for heating ingots that have insufficient amount of internal heat.

4

Bioceramic micro and nanoparticles as functional biological materials

Parakhonskiy B., Saveleva M., Svenskaya Y., Ivanova A., Lengert E., Alebastrova A., Yashchenok A., Gorin D., Bukreeva T., Marchenko I., Douglas T., Skirtach A.

Engineering of Biomaterials

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2017

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Vol. 20, no. 143 spec. iss.

77

5

On different approaches to syntactic analysis into bi-lexical dependencies : An empirical comparison of direct, PCFG-based, and HPSG-based parsers

Ivanova A., Oepen S., Dridan R., Flickinger D., Øvrelid L., Lapponi E.

Journal of Language Modelling

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2016

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Vol. 4, No. 1

113--144

EN

We compare three different approaches to parsing into syntactic, bilexical dependencies for English: a ‘direct’ data-driven dependenci parser, a statistical phrase structure parser, and a hybrid, ‘deep’ grammar-driven parser. The analyses from the latter two are postconverted to bi-lexical dependencies. Through this ‘reduction’ of All three approaches to syntactic dependency parsers, we determine empirically what performance can be obtained for a common set of dependenci types for English; in- and out-of-domain experimentation ranges over diverse text types. In doing so, we observe what trade-offs apply along three dimensions: accuracy, efficiency, and resilience to domain variation. Our results suggest that the hand-built grammar in one of our parsers helps in both accuracy and cross-domain parsing performance. When evaluated extrinsically in two downstream tasks – negation resolution and semantic dependency parsing – these accuracy gains do sometimes but not always translate into improved end-to-end performance.