scholarly journals Appendix B: Operational Tests Plans

2022 ◽  
pp. 235-237
Keyword(s):  
Author(s):  
Vyacheslav A. Denisov ◽  
Aleksandr Yu. Kostyukov ◽  
Roman N. Zadorozhniy

One of the most promising technologies for restoring machine parts and cylinder liners is electric spark treatment as the most versatile technology that provides high-quality restoration of worn parts with wear up to 0.5 mm. (Research purpose) The research purpose is in developing a technology for restoring various cylinder liners by means of electric spark processing, selecting optimal modes and electrode materials that allow improving the quality of repair and increasing the post-repair life of the sleeve. (Materials and methods) It was taken into account when conducting research aimed at restoring the geometric parameters of the sleeve, that the coating must have sufficient adhesion strength to the surface of the sleeve under mechanical, thermal loads and long-term operation. Laboratory studies of the adhesion strength of electric spark coatings on the separation (adhesive) and on the cut, as well as tribotechnical studies of interfaces were conducted. Authors have found by analyzing the results of operational tests of restored and new cylinder liners the prospects for using electric spark treatment of worn parts, including diesel engine liners. (Results and discussion) It was shown by laboratory studies of the adhesion strength of electric spark coatings with a 0.2 mm thick BrMKc 3-1 electrode to the working surface of cylinder liners that their separation strength (adhesive) was 20-40 megapascals, and the shear strength (cohesive) was 50-80 megapascals. It was found that this provides the required functional strength of coatings with maximum operational load. The article presents the results of comprehensive research in graphs and tables. (Conclusions) The research conducted in the CCP "Nano-Center" of the FSAC VIM and operational tests in the 2nd bus fleet of Moscow confirmed the principal possibility of effectively restoring cast iron liners (blocks) using the technology of electric spark processing.


2021 ◽  
Vol 18 (1) ◽  
pp. 80-94
Author(s):  
D. I. Prokhor ◽  
◽  
N. V. Grachev ◽  

Objective: An equivalent mode of accelerated thermal aging of the insulation system of electrical ma- chines is described to confirm the resource corresponding to a given period and operating conditions. Methods: The equivalent mode of accelerated heat aging was determined based on the Montzinger rule and tested in the course of research and development work (R&D) on the development, manufacture and implementation of a set of bench and operational tests of the insulation system of an increased heat resistance class of a diesel locomotive traction motor. Results: The relevance of R&D has been revealed, as a result of which the implementation of the idea was required, based on the statement about the re- duction of the insulation resource of electrical machines when the permissible heating is exceeded by 8–12 °С to various types of insulating materials. The advantages of the method presented in the article in relation to traditional solutions of this problem are demonstrated, and also improved consumer proper- ties of the traction electric motor of a diesel locomotive with a replaced insulation system of an increased class of heat resistance are presented. Generally, experimental tests and preliminary operational data are an acceptable basis for thermal evaluation of electrical insulating materials. However, it is important to remember that the scientific criterion is met and not to use the results of different types of tests in the analysis. Based on the world experience in diagnostics of additional insulation parameters for monitoring the state of insulation parameters, the possibility of using the “Doctor” series insulation monitoring de- vices has been determined and practically confirmed. Together with the results of subsequent operational tests, during which the insulation was also monitored using these mobile devices, it is argued that after carrying out the relevant research work, thanks to the mobile devices of the “Doctor” series, it is pos- sible to carry out predictive analytics of the failure of traction motors (TED) in any operating conditions. The functional value is determined and applied in practice. The “H” class insulation system developed by the specialists of JSC “VNIKTI” is mainly based on insulating materials produced by JSC “Holding Company „Elinar“”; the compound “Elplast 180ID” (JSC “Electroizolit”) or its analogue “Elkom-180” JSC “Holding company „Elinar“”), for anchor coils and equalizers, a wound PPIPK-2 wire in polyimide- fluoroplastic insulation (GC “Moskabelmet”) is used. Practical importance: It is stated that all stages of manufacturing and testing, determined at the initial stage of R&D, confirmed the results of the deve- lopment stages (overhaul (manufacture) of prototypes of TED using a new isolation system according to the design documentation of JSC “VNIKTI”). Bench tests have confirmed typical characteristics, speci- fied resource and insulation characteristics with equivalent accelerated thermal aging corresponding to an electric motor’s service life of 20 years in ordinary operation on a diesel locomotive, residual life of elements of the insulation system of naturally cut armature segments, main and auxiliary poles coils. In the specialized laboratory of JSC “Holding Company „Elinar“”, an experimental TED diesel locomotive set with the investigated insulation system was manufactured and installed on two sections of the main- line diesel locomotive 2TE116. Operational tests of an experimental TED diesel locomotive set under operating conditions were successful.


Coatings ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 287 ◽  
Author(s):  
Marina Volosova ◽  
Sergey Grigoriev ◽  
Alexander Metel ◽  
Alexander Shein

The main problem with ceramics used in cutting tools is related to the unpredictable failures caused by the brittle fracturing of ceramic inserts, which is critical for the intermittent milling of cyclic loading. A 125-mm-diameter eight-toothed end mill, with a mechanical fastening of ceramic inserts, was used as a cutting tool for milling hardened steel (102Cr6). For the experiments, square inserts of the Al2O3 + SiC ceramic were used and compared with the samples made of Al2O3 + TiC to confirm the obtained results. The samples were coated with diamond-like coating (DLC), TiZrN, and TiCrAlN coatings, and their bending strength and adhesion were investigated. Investigations into the friction coefficient of the samples and operational tests were also carried out. The effect of smoothing the microroughness and surface defects in comparison with uncoated inserts, which are characteristic of the abrasive processing of ceramics, was investigated and analyzed. The process developed by the authors of the coating process allows for the cleaning and activation of the surface of ceramic inserts using high-energy gas atoms. The impact of these particles on the cutting edge of the insert ensures its sharpening and reduces the radius of curvature of its cutting edges.


2018 ◽  
Vol 212 (1) ◽  
pp. 85-103
Author(s):  
Bogdan Pojawa

Abstract This article is a continuation to the theme of the article Operational diagnostics synthesis of the naval gas turbines operated by the Polish Navy published in SJ of PNA No. 1/2017. This article presents examples of results of energy research carried out by the Polish Naval Academy in the years 1985–2016, for the purpose of operational diagnostics of this type of engine, operated by the Polish Navy. The research conducted since 1985 covered four types of naval gas turbines (DE 59, DR 76, DR 77 and LM 2500), with a total of 24 engines. Currently in operation there are four LM 2500 type engines. In the near future, another LM 2500 engine will commence operations, along with a project 661M patrol ship. The energy research covers the engine start-up process, their operation in idle mode and within the whole range of load variations, as well as the process of engine stopping. The article presents examples of characteristics specific to the above processes, determined based on the results of studies of individual types of engines. Currently ongoing studies allow for constructing strategies for naval gas turbines, operated in the Polish Navy, according to technical condition.


1956 ◽  
Author(s):  
S. J. WEISS ◽  
K. KAMAMOTO ◽  
D. TAYLOR
Keyword(s):  

Author(s):  
Riccardo Scopigno

Vehicular Ad-Hoc Networks (VANETs) are wireless networks primarily meant to enforce vehicular safety. The incumbent international VANET solution is based on an adaptation of WLAN to the 5.9 GHz band and to the vehicular environment: it is universally known as IEEE 802.11p. One of the main reasons for the success of IEEE 802.11p lies on the functional requirement of a decentralized solution, that is, one able to work in the absence of infrastructure. While Filed-Operational Tests are being developed world-wide and new VANET applications, not restricted to safety, are being developed, new requisites are emerging. Some limitations of the IEEE 802.11p are coming to light as well: stakeholders must be aware of them to prevent misleading conclusions on reliability and, most importantly, improper solutions for the safety which the protocol is aimed at.


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