Wyniki wyszukiwania - Biblioteka Nauki

Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl

Ograniczanie wyników

Znaleziono wyników: 3

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Development and research of information model of ink combination process in multi-ink rotary web presses

100%

Shevchuk O.

nr 4

Prediction of transport vehicles’ durability with consideration of corrosive surface cracks propagation in structural elements

38%

Droździel P. , Popovych P. , Vitenko T. , Shevchuk O. , Zolotyi R. , Kononchuk O.

tom z. 101

47--57

Support frameworks of transport vehicles operate under varying terrain conditions under the influence of extreme climate and corrosive environments. When transporting cargo, dust is deposited on the surface of metal structures. The combination of dust and moisture creates an aggressive environment resulting in intense corrosion damage. The damage is caused by the defects of corrosion pitting, which occur on the surface and transform into corrosion cracks. Based on energy approaches, with the application of well-known results for the mathematical description of electrochemical reactions and the principles of fragile fracture mechanics, an analytical model of durability is proposed for the first time. The model determines the residual life of maximum loaded elements of undercarriages with surface cracks under the action of dynamic loads and corrosive environments. For this case, a set of mathematical relations in the form of a non-linear differential equation was developed, as well as the initial and final conditions for determining the life of vehicles’ structural elements with corrosive surface cracks. The analytical model implementation is proven by solving the problem of determining the residual life of a vehicle’s element, i.e., a steel plate, weakened by a semi-elliptical surface crack, which is under the action of dynamic loads in a 3% sodium chloride solution. The insignificant increase in the crack’s initial size is proven to greatly reduce the period of its subcritical growth. The developed model was applied to define the residual life of thin-walled elements of structures with surface cracks.

Gas hydrates impact on corrosion of the well flow lines material

32%

Poberezhny L. , Hrytsanchyk A. , Mandryk O. , Poberezhna L. , Popovych P. , Shevchuk O. , Mishchuk B. , Rudyak Y.

tom Vol. 110, nr 1

5--17

Purpose: Determination of regularities of joint action of mechanical stresses, formation water and hydrate formation on corrosion of material of flow pipelines. Design/methodology/approach: According to the analysis of reservoir water of the investigated deposits, it was found that the main corrosive component is soluble chlorides. Proposed for corrosion and corrosion-mechanical tests of 6 model environments. An estimation of the influence of stress concentration, depending on the defects of the inner wall of the pipe, was carried out, and the nominal local stresses in the pipeline was carried. Findings: The basic regularities of influence of stress and hydration formation on corrosion and localization of corrosion processes and on the kinetics of deformation of samples are described. For samples made of steel 20 and 17GS, an increase in the velocity of general and local corrosion for samples sustained in the gas hydrate was observed compared to the control results obtained, the coefficient of influence of the gas hydrate on corrosion was calculated. Research limitations/implications: The obtained results are valid for thermobaric operating conditions of well flow lines. Practical implications: The data obtained in the work on the patterns of corrosion processes and the impact of hydrate formation on them will allow to identify potentially dangerous areas of flow lines and prevent emergencies. Originality/value: Based on the analysis of the geometric dimensions of the defects, the effective stress concentration coefficients are calculated, and it is shown that the stresses in the vicinity of corrosion defects in normal operating modes range from 164 to 545 MPa.