In recent years accidents related to fracture of cast load-carrying elements of three-piece bogies of freight cars have become more frequent in the railways of Ukraine and Russia. The work substantiates the rationality of development and application of all-welded load-carrying elements of freight car bogie (FCB), improving their operational reliability. Welded structures of FCBs are widely applied in West Europe. Attempts to develop structures of all-welded elements of FCBs irreplaceable with cast structures are made in Ukraine and Russia. However, none of the developed welded structures is currently applied at regular cargo transportation, because of non-optimal design of bogie welded elements in terms of ensuring the required fatigue resistance margin. To develop a competitive welded solebar and bogie bolster it is, first of, all necessary to increase the fatigue resistance of bogie elements, improve the accuracy of solebar fabrication to avoid skewing of wheelset axles, leading to fast wear, lower their weight and cost, increase element run between scheduled depot repairs. Strength analysis of bogie welded elements should be performed in keeping with the norms currently in force, as well as current world standards, norms and recommendations, allowing for the most recent achievements in the field of dynamics of railway cars and methods to determine welded joint fatigue resistance. 20 Ref., 8 Figures.
Evaluation of load-carrying capacity of critical welded piping elements based on the results of technical diagnostics of their state is an important stage of a package of measures to confirm their operability and remaining safe operating life. In particular, in the case of detection of various defects of material discontinuity, it is necessary to perform static strength analysis of the piping and analysis of its strength factor correspondence to design requirements. If it is confirmed that the detected defects only slightly lower the piping load-carrying capacity, it can be allowed to operate in precised modes of force and corrosion impact. It is proposed to apply ductile fracture criterion based on multidimensional finite-element analysis of elastoplastic strain development. Admissibility of crack-like defects is substantiated by brittle-ductile fracture criteria. The case of an aluminium piping element of WWR-M research reactor primary circuit with detected multiple discontinuities of the weld (gas pores, nonmetallic inclusions) was used to show the sequence and main principles of analysis of defective piping load-carrying capacity. Community of the proposed methodological approaches allows their application at confirmation of operability of critical piping and pressure vessels from aluminium alloys and high-strength steels. 14 Ref., 1 Table, 7 Figures.
Statistics of accident rate at Ukrainian and Russian railways is an evidence of increase in the recent years of the accidents, related with failure of cast bearing elements of two-axle three-component freight car bogies. Analysis of service reliability of cast structures of side frame and bolster of 18-100 type bogie shows that appearance of fatigue cracks is the main reason of reject. It is reasonable to search an alternative application of welding technologies in manufacture of indicated parts from sheet products for the purpose of increase of their safety and survivability. It is shown that existing Norms for designing of welded joints and assemblies of railway cars significantly overstate real cyclic load resistance of welded joints in comparison with the Recommendations of the International Institute of Welding. This disadvantage is typical for number of reference documents acting in Russia and Ukraine, which regulate calculation of fatigue resistance of welded joints and assemblies. This promotes negative results in designing with respect to required life of welded elements. Development of safe and technological welded elements of freight car bogie requires application of the recent achievements in the field of fatigue strength of welded joints. 13 Ref., 4 Tables.
Ìîäåëþâàííÿ çàëèøêîâèõ òåõíîëîã³÷íèõ íàïðóaeåíü â çîí³ çâàðíèõ ç'ºäíàíü îáè÷àéîê êîðïóñó ðåàêòîðà òèïó ÂÂÅÐ-1000 Ïðîàíàë³çîâàíî êîíñòðóêòèâí³ îñîáëèâîñò³ òà òåõíîëîã³þ çâàðþâàííÿ êîðïóñó ðåàêòîðà. Âèêëàäåíî ìåòîäèêó ðîçðàõóíêîâîãî âèçíà÷åííÿ çâàðþâàëüíèõ çàëèøêîâèõ íàïðóaeåíü. Ïîáóäîâàíî ìîäåë³ äåôîðìàö³éíèõ ïðîöåñ³â òà ðîçïîä³ëó òåìïåðàòóðè ïðè çâàðþâàëüíîìó íàãð³â³. Âèêîíàíî ìîäåëþâàííÿ íàïðóaeåíîãî ñòàíó ïðè çâàðþâàíí³, íàïëàâëåíí³ ³ òåðìîîáðîáö³ ê³ëüöåâîãî ç'ºäíàííÿ êîðïóñó ðåàêòîðà ÂÂÅÐ-1000. Íàâåäåíî ðåçóëüòàòè ïðîñòåaeóâàííÿ ðîçâèòêó íàïðóaeåíü â ïðîöåñ³ âèêîíàííÿ çâàðþâàííÿ, íàïëàâëåííÿ ³ òåðìîîáðîáêè çâàðíîãî ç'ºäíàííÿ êîðïóñó ðåàêòîðà ÂÂÅÐ-1000. Âèêîíàíî ïîð³âíÿííÿ ðîçðàõóíêîâèõ çíà÷åíü çàëèøêîâèõ íàïðóaeåíü â çîí³ çâàðíîãî ç'ºäíàííÿ ç åêñïåðèìåíòàëüíèìè äàíèìè. Ê ë þ ÷ î â ³ ñ ë î â à: êîðïóñ ðåàêòîðà, ìåòîä ñê³í÷åíèõ åëåìåíò³â, çâàðþâàëüí³ çàëèøêîâ³ íàïðóaeåííÿ, ìîäåë³ äåôîðìàö³éíèõ ïðîöåñ³â, ðîçïîä³ë òåìïåðàòóðè.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.