ТЕХНИЧЕСКИ УНИВЕРСИТЕТ - ГАБРОВО
ПЕРСОНАЛНА И ПРОФЕСИОНАЛНА ИНФОРМАЦИЯ НА ПРЕПОДАВАТЕЛ
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Име: ВЛАДИМИР ПЕТРОВ ДУНЧЕВ
Месторабота: Технически университет - Габрово
Длъжност (звание): Доцент, висше училище
Научна степен: Доктор (научно-образователна), Технически науки
Факултет: Машиностроене и уредостроене
Катедра: Материалознание и механика на материалите
Кабинет(и): 1226
Служебен тел.: 066827306
E-mail1:
Съдържание:
Книги (2)
Публикации (63)


Публикации
Публикация: №1 Владимир Петров Дунчев, Методично ръководство са решаване на задачи по Статика, УНЕВЕРСИТЕТСКО ИЗДАТЕЛСТВО „ВАСИЛ АПРИЛОВ“ ГАБРОВО, 2020, ISBN 978-954-683-623-6
Издателство: УНЕВЕРСИТЕТСКО ИЗДАТЕЛСТВО „ВАСИЛ АПРИЛОВ“ ГАБРОВО
Изд.год.: 2020
Вид: Книга (бълг.издание)

Публикация: №2 Владимир Петров Дунчев, Ръководство са решаване на задачи по Кинематика, УНЕВЕРСИТЕТСКО ИЗДАТЕЛСТВО „ВАСИЛ АПРИЛОВ“ ГАБРОВО, 2020, ISBN: 978-954-683-627-4
Издателство: УНЕВЕРСИТЕТСКО ИЗДАТЕЛСТВО „ВАСИЛ АПРИЛОВ“ ГАБРОВО
Изд.год.: 2020
Вид: Книга (бълг.издание)

Публикация: №3 Maximov, J.M.; Duncheva, G.V.; Anchev, A.P.; Dunchev, V.P.; Anastasov, K.; Daskalova, P.H. Effect of Roller Burnishing and Slide Roller Burnishing on Surface Integrity of AISI 316 Steel: Theoretical and Experimental Comparative Analysis. Machines, 2024, 12, 51
Издателство: MDPI
Изд.год.: 2024
Вид: Научна публикация - Статия в чужд. списание

Публикация: №4 Maximov, J.; Duncheva, G.; Anchev, A.; Dunchev, V.; Argirov, Y. Improvement in Fatigue Strength of Chromium–Nickel Austenitic Stainless Steels via Diamond Burnishing and Subsequent Low-Temperature Gas Nitriding. Appl. Sci. 2024, 14, 1020
Издателство: MDPI
Изд.год.: 2024
Вид: Научна публикация - Статия в чужд. списание

Публикация: №5 Padikova, F.; Nedeva, D.; Dunchev, V.; Stoyanov, B.; Ormanova, M.; Nedyalkov, N.; Valkov, S. Fabrication and Characterization of Titanium Borides by Electron Beam Surface Alloying. Coatings 2023, 13, 1941. https://doi.org/10.3390/coatings13111941
Издателство: Coatings, MDPI
Изд.год.: 2023
Вид: Научна публикация - Статия в чужд. списание
Пълен текст:

Публикация: №6 Anchev, A.; Kaisheva, D.; Kotlarski, G.; Dunchev, V.; Stoyanov, B.; Ormanova, M.; Atanasova, M.; Todorov, V.; Daskalova, P.; Valkov, S. Welding of Ti6Al4V and Al6082-T6 Alloys by a Scanning Electron Beam. Metals 2023, 13, 1252. https:// doi.org/10.3390/met13071252
Издателство: Metals, MDPI
Изд.год.: 2023
Вид: Научна публикация - Статия в чужд. списание
Пълен текст:

Публикация: №7 Dunchev V.P., P.H. Daskalova, Experimental study of residual stresses around fastener holes in 2024-T3 aluminum alloy via modified split mandrel method. International Scientific Conference, “ Mechatronic, Eco – and energy saving systems and technology”. Gabrovo. 2023 p.136-151 ISSN 2815-4924
Издателство: International Scientific Conference, “ Mechatronic, Eco – and energy saving systems and technology”. Gabrovo
Изд.год.: 2023
Вид: Научна публикация - Доклад от межд. конф. в Б-я

Публикация: №8 Anchev A. P., V.P.Dunchev, P.H. Daskalova, Fatigue behavior experimental study of specimens with fastener holes in 2024-T3 aluminum alloy subjected to cold expansions via modified split mandrel method. International Scientific Conference, “ Mechatronic, Eco – and energy saving systems and technology”. Gabrovo. 2023 p.155-164 ISSN 2815-4924
Издателство: International Scientific Conference, “ Mechatronic, Eco – and energy saving systems and technology”. Gabrovo
Изд.год.: 2023
Вид: Научна публикация - Доклад от межд. конф. в Б-я

Публикация: №9 Valkov, S., D. Nedeva, Vl. Dunchev, F. Padikova, M. Ormanova, B. Stoyanov, N. Nedyalkov, Fabrication and Characterization of Ti/TiC Composite Layers by an Electron-Beam Surface Modification, journal Coatings, volume 13, Issue 5 (May 2023), article 951,IF 3.4, Q2
Издателство: Journal Coatings, MDPI
Изд.год.: 2023
Вид: Научна публикация - Статия в чужд. списание

Публикация: №10 Padikova F., D. Nedeva, B.Stoyanov, V.Dunchev, Maria Ormanova, G. Kotlarski, S.Valkov, SYNTHESES, STRUCTURE AND MECHANICAL PROPERTIES OF COMPOSITE LAYERS IN THE SYSTEM TI-B OBTAINED BY A SCANNING ELECTRON BEAM, pp 60-65, ISSN: 2815-4924
Издателство: Университетско издателство “Васил Априлов” – Габрово
Изд.год.: 2023
Вид: Научна публикация - Доклад от межд. конф. в Б-я

Публикация: №11 Duncheva G, Maximov J, Anchev A, Dunchev V, Argirov Y, Velkov S, Modeling and Optimization of Surface Integrity and Sliding Wear Resistance of Diamond-Burnished Holes in Austenitic Stainless Steel Cylinder Lines. Machines 11 872
Издателство: MDPI
Изд.год.: 2023
Вид: Научна публикация - Статия в чужд. списание
Пълен текст:

Публикация: №12 Maximov JT, Duncheva GV, Anchev AP, Dunchev VP, Argirov YB, Nikolova MP. Effects of heat treatment and diamond burnishing on fatigue behaviour and corrosion resistance of AISI 304 austenitic stainless steel. Applied Sciences, 2023, 13, 2570
Издателство: MDPI
Изд.год.: 2023
Вид: Научна публикация - Статия в чужд. списание

Публикация: №13 Kaisheva D, Anchev A, Dunchev V, Kotlarski G, Stoyanov B, Ormanova M, Valkov S. Electron-Beam Welding Cu and Al6082T6 Aluminum Alloys with Circular Beam Oscillations. Crystals. 2022; 12(12):1757.
Издателство: MDPI
Изд.год.: 2022
Вид: Научна публикация - Статия в чужд. списание

Публикация: №14 Dikova Ts., A. Anchev, V. Dunchev, D. Dzhendov, Y. Gagov. Experimental investigation of adhesion strength of dental ceramic to Ti6Al4V alloy fabricated by milling and selective laser melting. Procedia Structural Integrity, 42 (2022) 1520-1528. ISSN 2452-3216
Издателство: Elsevier
Изд.год.: 2022
Вид: Научна публикация - Статия в чужд. списание

Публикация: №15 Duncheva G.V., Maximov J.T. , Anchev A.P. , V.P. Dunchev V.P. , Argirov Y.B., Kandeva-Ivanova M., Enhancement of the wear resistance of CuAl9Fe4 sliding bearing bushings via diamond burnishing. Wear 510–511 (2022) 204491.
Издателство: Elsevier, Wear
Изд.год.: 2022
Вид: Научна публикация - Статия в чужд. списание

Публикация: №16 Maximov JT, Duncheva GV, Anchev AP, Dunchev VP, Argirov YB. Effect of Diamond Burnishing on Fatigue Behaviour of AISI 304 Chromium-Nickel Austenitic Stainless Steel. Materials. 2022; 15(14):4768. https://doi.org/10.3390/ma15144768
Издателство: MDPI
Изд.год.: 2022
Вид: Научна публикация - Статия в чужд. списание

Публикация: №17 Kaisheva, D.; Anchev, A.; Valkov, S.; Dunchev, V.; Kotlarski, G.; Stoyanov, B.; Ormanova, M.; Atanasova, M.; Petrov, P. Influence of Beam Power on Structures and Mechanical Characteristics of Electron-Beam-Welded Joints of Copper and Stainless Steel. Metals 2022, 12, 737
Издателство: Metals 2022, 12, 737
Изд.год.: 2022
Вид: Научна публикация - Статия в чужд. списание
Абстракт: In this study, we present the results of electron-beam welding of joints with 304-L stainless steel and copper. The influence of the beam’s power on the structures and mechanical properties of the welded joints was studied; the experiments were realized at a beam deflection of 0.3 mm to the Cu plate and beam powers of 2400, 3000, and 3600W. The phase compositions of the obtained welded joints were studied by using X-ray diffraction (XRD); the microstructure and chemical composition were investigated by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX), respectively. The mechanical properties were studied by using tensile experiments and microhardness investigations. The phase compositions of the welded joints were in the forms of substitutional solid solutions between Fe, Cu, and pure copper and remained unchanged in terms of power. It was found that the microstructures changed gradually with the application of different values of the power of the electron beam. The results of the tensile tests showed higher tensile strengths at lower beam powers (i.e., 2400 and 3000 W) that dropped at 3600W. The relative elongations rose with increases in the power of the electron beam. Moreover, it was found that the microhardnesses strongly depended on the applied technological conditions (defined by the electron beam’s power) and the corresponding microstructures of the welded joints.
Web: https://doi.org/10.3390/met12050737
Пълен текст:

Публикация: №18 Kaisheva D., A. Anchev, V. Dunchev, B. Stoyanov, S. Valkov, M. Ormanova , G. Kotlarski, V. Todorov, M. Atanasova, P. Petrov. Welding of copper and 304L stainless steel with continuous electron beam. Bulgarian Chemical Communications, 54 (B2) (2022) 78-81
Издателство: БАН Институт по Инженерна Химия
Изд.год.: 2022
Вид: Научна публикация - Статия в бълг. списание

Публикация: №19 Duncheva GV, Maximov JT, Anchev AP, Dunchev VP, Argirov YB, Ganev N, Drumeva DK. Improvement of surface integrity of CuAl8Fe3 bronze via diamond burnishing. Int J Adv Manuf Technol (2022) DOI: 10.1007/s00170-022-08664-9
Издателство: SPRINGER
Изд.год.: 2022
Вид: Научна публикация - Статия в чужд. списание
Абстракт: The single-phase CuAl8Fe3 aluminum bronzes possess good strength and resistance to fatigue as well as high corrosion and wear resistance. Since this alloy contains less than 8.5% aluminum, it cannot be heat treated. Therefore, improvements in surface integrity (SI) can only be achieved via mechanical surface treatment. This article investigates the influence of the basic diamond burnishing (DB) process, as well as additional factors, on the SI characteristics of CuAl8Fe3 bronze. Using experiments and regression analyses, a multi-objective optimization of the DB process has been accomplished via non-dominated sorting genetic algorithm (NSGA-II) and optimal values of the factors have been established. Using these factor values, the SI characteristics of diamond-burnished CuAl8Fe3 specimens have been quantified. The conclusion has been reached that the DB of CuAl8Fe3 bronze can be implemented as mixed burnishing, i.e., DB results in a favorable combination of the height and shape parameters for the surface texture, very low roughness (nearly mirror surfaces), large (in absolute value) residual hoop and axial stresses at depths greater than 0.8 mm, high surface micro-hardness and strongly expressed grain-refined microstructures at depths of up to 0.15 mm. These SI characteristics suggest a significant increase in fatigue strength and wear resistance of CuAl8Fe3 bronze finished via DB.
Web: https://doi.org/10.1007/s00170-022-08664-9

Публикация: №20 Kaisheva D., Kotlarski G., Stoyanov B., Dunchev V., Ormanova M., Valkov S. Electron beam welding of dissimilar metals and alloys. Unitech 2022 Gabrovo, 18-19 November, 2022, II-367 - II-372
Издателство: Unitech 2022
Изд.год.: 2022
Вид: Научна публикация - Доклад от межд. конф. в Б-я

Публикация: №21 Duncheva GV, Maximov JT, Anchev AP, Dunchev VP, Argirov YB, Ganev N, Drumeva DK. Improvement of surface integrity of CuAl8Fe3 bronze via diamond burnishing. Int J Adv Manuf Technol (2022) DOI: 10.1007/s00170-022-08664-9
Издателство: SPRINGER
Изд.год.: 2022
Вид: Научна публикация - Статия в чужд. списание

Публикация: №22 Vladimir Todorov, Vladimir Dunchev, INVESTIGATION OF THE INFLUENCE OF THE INITIAL MICROSTRUCTURE UNDER DIFFERENT MODES OF HEAT TREATMENT ON THE MECHANICAL PROPERTIES OF 35CrMnSi STEEL, Journal of the Technical University of Gabrovo 64 (2022) 50-55
Издателство: Journal of the Technical University of Gabrovo
Изд.год.: 2022
Вид: Научна публикация - Статия в бълг. списание

Публикация: №23 Kaisheva D., A. Anchev, V. Dunchev, B. Stoyanov, S. Valkov, M. Ormanova, G. Kotlarski, V. Todorov, M. Atanasova, S. Rabadzhiyska and P. Petrov, „Study of the structure and mechanical properties of electronbeam-welded dissimilar joints of copper and stainless steel with and without offset“, VEIT-2021, Journal of Physics: Conference Series, IOP Publishing, 2022
Издателство: VEIT-2021, Journal of Physics
Изд.год.: 2021
Вид: Научна публикация - Статия в чужд. списание
Абстракт: We present the results of an investigation of the structure and mechanical properties of dissimilar joints of copper and 304L stainless steel formed by electron-beam welding. The samples studied were welded without a beam offset and with a beam offset towards either welded materials to a distance of 0.3 mm. The phase composition was determined via X-ray analysis. The structure was investigated using scanning electron microscopy. The mechanical properties, including hardness and tensile strength, were measured. The phase composition of the considered specimens consisted of a double-phase structure of face-centered cubic (fcc) and body-centered cubic (bcc) phases. The sample welded without offset exhibited the highest yield strength and tensile strength values. The microhardness of all samples increased in the fusion zone on the steel side and decreased in the fusion zone on the copper side compared to the initial hardness of the two materials.
Web: http://dx.doi.org/10.1088/1742-6596/2240/1/012006
Пълен текст:

Публикация: №24 Вл. П. Дунчев, Температуро-зависим конститутивен модел на повърхностния слой на високо-легирана стомана AISI316Ti, подложена на диамантно заглаждане, Машиностроене и машинознание 31 (2021) ISSN 1312-8612
Издателство: Машиностроене и машинознание
Изд.год.: 2021
Вид: Научна публикация - Статия в бълг. списание

Публикация: №25 Вл. П. Дунчев, Влияние на скоростта на плъзгане върху surface integrity при диамантно заглаждане на образци от високо-легирана стомана AISI316Ti. Част I: Експериментално изследване на грапавостта и микротвърдостта, Машиностроене и машинознание 31 (2021) ISSN 1312-8612
Издателство: Машиностроене и машинознание
Изд.год.: 2021
Вид: Научна публикация - Статия в бълг. списание

Публикация: №26 Вл. П. Дунчев, Влияние на скоростта на плъзгане върху surface integrity при диамантно заглаждане на образци от високо-легирана стомана AISI316Ti. Част II: Числени симулации за изследване на остатъчните напрежения, Машиностроене и машинознание 31 (2021) ISSN 1312-8612
Издателство: Машиностроене и машинознание
Изд.год.: 2021
Вид: Научна публикация - Статия в бълг. списание

Публикация: №27 Maximov JT, Duncheva GV, Dunchev VP, Anchev AP. Different strategies for finite element simulations of static mechanical surface treatment processes—a comparative analysis. J Braz. Soc. Mech. Sci. Eng. 43, 371 (2021). https://doi.org/10.1007/s40430-021-03085-3
Издателство: SPRINGER
Изд.год.: 2021
Вид: Научна публикация - Статия в чужд. списание

Публикация: №28 Duncheva GV, Maximov JT, Anchev AP, Dunchev VP, Argirov Ya. B., Improvement in Wear Resistance Performance of CuAl8Fe3 Single-Phase Aluminum Bronze via Slide Diamond Burnishing. Journal of Materials Engineering and Performance (2021) doi.org/10.1007/s11665-021-06389-6
Издателство: Springer
Изд.год.: 2021
Вид: Научна публикация - Статия в чужд. списание

Публикация: №29 Duncheva GV, Maximov JT, Anchev AP, Dunchev VP, Argirov Ya.B,, Multi-objective optimization of the internal diamond burnishing process. Materials and Manufacturing Processes (2021) DOI: 10.1080/10426914.2021.1981937
Издателство: Taylor & Francis
Изд.год.: 2021
Вид: Научна публикация - Статия в чужд. списание

Публикация: №30 Duncheva, GV, Maximov, JT, Anchev, AP, Dunchev VP, Argorov YB, Ganev N, Capek J, Fatigue strength improvement in CuAl8Fe3 bronze via diamond burnishing. J Braz. Soc. Mech. Sci. Eng. 43, 569 (2021). https://doi.org/10.1007/s40430-021-03296-8
Издателство: Springer
Изд.год.: 2021
Вид: Научна публикация - Статия в чужд. списание

Публикация: №31 Duncheva GV, Maximov JT, Anchev AP, Dunchev VP, Atanasov TP, Capek J. Finite element and experimental study of the residual stresses in 2024-T3 Al alloy treated via single toroidal burnishing. J Braz Soc Mech Sci Eng (2021) DOI: 10.1007/s40430-020-02775-8
Издателство: SPRINGER
Изд.год.: 2021
Вид: Научна публикация - Статия в чужд. списание

Публикация: №32 Maximov JT, Duncheva GV, Anhev AP, Dunchev VP, Capec J. A cost-effective optimization approach for improving the fatigue strength of diamond-burnished steel components. J Braz Soc Mech Sci Eng 43(1), 33 (2021)
Издателство: SPRINGER
Изд.год.: 2021
Вид: Научна публикация - Статия в чужд. списание

Публикация: №33 Duncheva GV, Maximov JT, Anchev AP, Dunchev VP, Atanasov TP, Improvement in Fatigue Performance of 2024-T3 Al Alloy Via Single Toroidal Roller Burnishing. Journal of Materials Engineering and Performance (2021) DOI:10.1007/s11665-021-05535-4
Издателство: Springer
Изд.год.: 2021
Вид: Научна публикация - Статия в чужд. списание

Публикация: №34 Вл. Дунчев, Д. Друмева. Крайно-елементен анализ на процеса диамантно заглаждане на отвори в алуминиев бронз CuAl8Fe3. Известия на Технически университет-Габрово. 62 (2021) 17-23, ISSN 1310-6686
Издателство: Известия на Технически университет-Габрово. 62 (2021)
Изд.год.: 2021
Вид: Научна публикация - Статия в бълг. списание
Абстракт: This article presents the results obtained from finite element (FE) analysis of the diamond burnishing process of holes in sliding bearingsmade of CuAl8Fe3 aluminum bronze. For this purpose, a fully coupled 3D FE model of the studied process was developed. The model makes it possible to assess both the temperature effect and the stressed and strained state in the surface layers around the hole. It was found that in diamond burnishing the temperature athole surface pointsis characterized by a strong gradient, reaching a maximum value , after that it decreases very quickly. Based on the FE results for the equivalent plastic strain Tmax,A= 54.284 C, distribution in a depth, it was found that the hardened layer has a thickness of mm 75.0. The diamond burnishing process provides an intensive compressive zone with useful hoop residual stresses in the surface layers around the hole in CuAl8Fe3 bronze sliding bearings.

Публикация: №35 Вл. Дунчев, Д. Друмева. Температуро-зависим конститутивен модел на повърхностния слой на бронз CuAl8Fe3 подложен на диамантно заглаждане. Известия на Технически университет-Габрово, бр. 61 (2020) 22-28, ISSN 1310-6686.
Издателство: Известия на Технически университет-Габрово 61
Изд.год.: 2020
Вид: Научна публикация - Статия в бълг. списание
Абстракт: In this article, the temperature-dependent constitutive model of CuAl8Fe3 bronze is developed, using the "flow stress"concept. The model defines the dependence between the stress and strain tensors for a point on the surface layer subjected to diamond burnishing. The adequacy of the chosen constitutive model was achieved by comparing the deformed state of the surface layer obtained via an experimental test (indentation test) and inverse finite element analysis of the experimental test. The developed constitutive model takes into account the temperature influence on the surface and sub-surface layers of CuAl8Fe3 bronze in the range of (20 ÷ 250) ° C . The model serves the fully coupled thermal-stress finite element analysis in order to study the stressed and strained state in rotational components made of bronze CuAl8Fe3, subjected to diamond burnishing.

Публикация: №36 Вл. Дунчев, Д. Друмева. Моделиране и оптимизация на грапавостта и микротвърдостта при диамантно заглаждане на бронз CuAl8Fe3 подложен на диамантно заглаждане. Известия на Технически университет-Габрово 61 (2020) 29-42, ISSN 1310-6686.
Издателство: Известия на Технически университет-Габрово 61 (2020)
Изд.год.: 2020
Вид: Научна публикация - Статия в бълг. списание
Абстракт: In this article, the object of the experimental study is diamond burnishing of cylindrical specimens made of bronze CuAl8Fe3 in terms of the roughness obtained and microhardness. For this purpose, planned experiment, analysis of variance and regression analysis were performed sequentially. The governing factors were the spherical surface radius of the diamond tip, burnishing force and feed rate. Based on the regression models obtained of the roughness and surface microhardness, one-objective optimizations under the minimum roughness criterion and maximum surface microhardness, and two-objective optimization of the studied process were conducted. As a result, the respective optimal values of the governing factors were established. Using the governing factor optimal values obtained from the two-objective optimization, the impact of the number of passes and working scheme (one-way or two-way) on the roughness obtained and surface microhardness was additionally studied.

Публикация: №37 Maximov JT, Duncheva GV, Anchev AP, Dunchev VP. Slide burnishing versus deep rolling – a comparative analysis. Int J Adv Manuf Technol 110 (2020) 1923-1939
Издателство: SPRINGER
Изд.год.: 2020
Вид: Научна публикация - Статия в чужд. списание

Публикация: №38 Duncheva GV, Maximov JT, Dunchev VP, Anhev AP, Atanasov TP, Capec J. Single toroidal roller burnishing of 2024T3 Al alloy implemented as mixed burnishing process. Int J Adv Manuf Technol (2020) DOI: 10.1007/s00170-020-06350-2.
Издателство: Springer
Изд.год.: 2020
Вид: Научна публикация - Статия в чужд. списание

Публикация: №39 V. P. Dunchev, Comprehensive model of the micro-hardness of diamond burnished 41Cr4 steel specimens, Journal of the Technical University of Gabrovo, 60 (2020) 25-33
Издателство: Journal of the Technical University of Gabrovo
Изд.год.: 2020
Вид: Научна публикация - Статия в бълг. списание

Публикация: №40 V. P. Dunchev, M. D. Ichkova, Finite element simulations of static mechanical surface treatment processes – a review and prospects, Journal of the Technical University of Gabrovo, 60 (2020) 14-24
Издателство: Journal of the Technical University of Gabrovo
Изд.год.: 2020
Вид: Научна публикация - Статия в бълг. списание

Публикация: №41 V. P. Dunchev, P. P. Peneva, Temperature-dependent constitutive model of the surface layer of 2024-T3 aluminum alloy subjected to surface plastic deformation, Journal of the Technical University of Gabrovo, 60 (2020) 79-85
Издателство: Journal of the Technical University of Gabrovo
Изд.год.: 2020
Вид: Научна публикация - Статия в бълг. списание

Публикация: №42 Т. П. Атанасов, А. П. Анчев, Вл. П. Дунчев, Експериментално изследване на получената грапавост в образци от алуминиева сплав 2024-Т3, подложени на ППД с тороидална ролка, Машиностроене и машинознание 30 (2020) 44-48
Издателство: Машиностроене и машинознание
Изд.год.: 2020
Вид: Научна публикация - Статия в бълг. списание

Публикация: №43 V. P. Dunchev, D. K. Drumeva, Modeling and optimization of the roughness and microhardness in diamond burnishing of CuAl9Fe3 bronze, Journal of the Technical University of Gabrovo, 61 (2020) 29-42
Издателство: Journal of the Technical University of Gabrovo
Изд.год.: 2020
Вид: Научна публикация - Статия в бълг. списание

Публикация: №44 V. P. Dunchev, D. K. Drumeva, Surface layer Temperature-dependent constitutive model of bronze CuAl8Fe3, subjected to diamond burnishing, Journal of the Technical University of Gabrovo, 61 (2020) 22-28
Издателство: Journal of the Technical University of Gabrovo
Изд.год.: 2020
Вид: Научна публикация - Статия в бълг. списание

Публикация: №45 V. P. Dunchev, Effect of diamond burnishing process velocity on 41Cr4 steel surface integrity, Journal of the Technical University of Gabrovo, 61 (2020) 3-7
Издателство: Journal of the Technical University of Gabrovo
Изд.год.: 2020
Вид: Научна публикация - Статия в бълг. списание

Публикация: №46 V. P. Dunchev, Effect of sliding velocity on microstructure of diamond burnished 41Cr4 steel components, Journal of the Technical University of Gabrovo, 61 (2020) 43-51
Издателство: Journal of the Technical University of Gabrovo
Изд.год.: 2020
Вид: Научна публикация - Статия в бълг. списание

Публикация: №47 V. P. Dunchev, J. Capek, M. Atanasov, Effect of ion nitriding on fatigue befavior of steel 35HGS, Journal of the Technical University of Gabrovo, 58 (2019) 20-25
Издателство: Journal of the Technical University of Gabrovo
Изд.год.: 2019
Вид: Научна публикация - Статия в бълг. списание
Пълен текст: Изтегли

Публикация: №48 V. P. Dunchev, A. P. Anchev, Experimental study of the roughness of low carbon, medium carbon and tool steel after diamond burnishing, Journal of the Technical University of Gabrovo, 58 2019) 26-32
Издателство: Journal of the Technical University of Gabrovo
Изд.год.: 2019
Вид: Научна публикация - Статия в бълг. списание

Публикация: №49 Maximov JT, Duncheva GV, Anchev AP, Dunchev VP. Crack resistance enhancement of joint bar holes by slide diamond burnishing using new tool equipment. Int J Adv Manuf Technol 102 (2019) 3151-3164
Издателство: SPRINGER
Изд.год.: 2019
Вид: Научна публикация - Статия в чужд. списание

Публикация: №50 Maximov JT, Duncheva GV, Anchev AP, Ganev N, Dunchev VP. Effect of cyclic loading on fatigue performance of slide burnishing components made of low-alloy medium carbon steel. Fatigue Fract Eng Mater Struct 42(6) (2019) 1414-1425
Издателство: WILEY
Изд.год.: 2019
Вид: Научна публикация - Статия в чужд. списание

Публикация: №51 Maximov JT, Duncheva GV, Anchev AP, Dunchev VP. Smoothing, deep or mixed diamond burnishing of low-alloy steel components – optimization procedures. Int J Adv Manuf Technol 106 (2020) 1917-1929
Издателство: SPRINGER
Изд.год.: 2019
Вид: Научна публикация - Статия в чужд. списание
Абстракт: Diamond burnishing (DB) is a static mechanical surface treatment based on severe surface plastic deformation aimed at significant improvement in the surface integrity and operating properties of the treated component. Very often, DB is unjustifiably perceived of as typical smoothing burnishing. In the present article, it is shown that DB can be conducted as smoothing, deep or mixed burnishing depending on the particular combination of process governing factors employed. Optimizations of the DB process for 41Cr4 steel under different criteria are conducted in order to obtain the optimal parameters of different DB processes. The choices of governing factors and objective functions (roughness and fatigue limits), which are obtained on the basis of planned experiments and regression analyses, are fully justified. By means of one-objective optimizations, the uncompromising optimum values of the objective functions and the corresponding optimum values of the governing factors of smoothing and deep DB processes are obtained. A new optimization procedure for solving a multi-objective optimization task is developed in order to obtain compromise optimal values simultaneously with the objective functions and governing factors of the mixed DB process. In order to highlight the advantages of the proposed optimization procedure, the multi-objective task solution is compared with the results obtained via some known methods, i.e., the compromise weight vector and function of the losses methods.

Публикация: №52 Maximov JT, Dunchev VP. Investigation of dynamic response of "bridge girder - telpher - load" crane system due to telpher motion. Coupled Systems Mechanics 7(4) (2018) 485-507
Издателство: TECHNO-PRESS
Изд.год.: 2018
Вид: Научна публикация - Статия в чужд. списание

Публикация: №53 Maximov JT, Anchev AP, Duncheva GV, Ganev N, Selimov KF, Dunchev VP. Impact of slide diamond burnishing additional parameters on fatigue behaviour of 2024-T3 Al alloy. Fatigue Fract Eng Mater Struct. 42(1) (2019) 363-373
Издателство: WILEY
Изд.год.: 2018
Вид: Научна публикация - Статия в чужд. списание

Публикация: №54 Maximov JT, Anchev AP, Dunchev VP, Ganev N, Duncheva GV, Selimov KF. Effect of slide burnishing basic parameters on fatigue performance of 2024-T3 high-strength aluminium alloy. Fatigue and Fracture of Engineering Materials and Structures 40(11) (2017) 1893-1904
Издателство: John Wiley & Sons Ltd
Изд.год.: 2017
Вид: Научна публикация - Статия в чужд. списание
Абстракт: The effect of slide burnishing (SB) on the high cycle fatigue performance (HCF) of 2024-T3 high-strength aluminum alloy has been studied. After SB with optimum basic process parameters under “minimum roughness” criterion, the cycles fatigue strength increases with - from to , fatigue life is increased more than 50 times and the roughness obtained reaches up to . Further, various combinations of burnishing force and deforming element radius have been applied to reach maximum HCF performance despite roughness obtained. It has been established that with the optimum combination under “maximum HCF performance” criterion, cycles fatigue strength increases with - from to as the roughness obtained is . This significant enhancement in the HCF performance is due to introduced beneficial residual compressive stresses. They shift the fatigue crack initiation site from surface to subsurface layers and, as a result, the nucleation and propagation of the first-mode fatigue cracks are retarded. In order to establish the fatigue limit (based on cycles), a combined approach, based on limited Wöhler’s curve and Locati’s method, has been applied. The fatigue limit of 2024-T3 high-strength aluminum alloy can be increased up to using SB with optimal basic parameters under “maximum HCH performance” criterion.

Публикация: №55 Дунчев В. П., Й. Т. Максимов Й. Т. Принудени колебания на системата „главна греда – телфер – товар” следствие движение на телфера. Механика на Машините 109 (2015) 13-17.
Издателство: Технически университет Варна
Изд.год.: 2015
Вид: Научна публикация - Статия в бълг. списание

Публикация: №56 В. П. Дунчев, Информационно – изчислителна система за офериране и оптимално проектиране на металната конструкция на мостови кранове. Международна научна конференция UNITECH 2014 Габрово, 21 - 22 ноември, 2014, III-107 - III-118.
Издателство: Международна научна конференция UNITECH 2014 Габрово
Изд.год.: 2014
Вид: Научна публикация - Доклад от межд. конф. в Б-я

Публикация: №57 Дунчев В. П., Максимов Й. Т. Трептене на греда на Bernoulli - Euler с ъглови опори под действие на преминаващ товар. Механика на машините 105 (2014) 17 - 24.
Издателство: Технически университет Варна
Изд.год.: 2014
Вид: Научна публикация - Статия в бълг. списание

Публикация: №58 Дунчев В. П ., Й. Т. Максимов Й. Т. Динамично поведение на системата „главна греда – телфер – товар” следствие движение на телфера . Известия на Технически университет Габрово 48 ( 2014 ) 3 - 9 .
Издателство: Издателство "Васил Априлов" - ТУ-Габрово
Изд.год.: 2014
Вид: Научна публикация - Статия в бълг. списание

Публикация: №59 В. П. Дунчев , Методика за оптимално проектиране на главната греда с кутиеобразно напречно сечение на едногредов мостов кран. Международна научна конференция UNITECH 2013 Габрово, 22 - 23 ноември, 2013, III - 88 – III - 91.
Издателство: Международна научна конференция UNITECH 2013 Габрово
Изд.год.: 2013
Вид: Научна публикация - Доклад от межд. конф. в Б-я

Публикация: №60 Максимов Й. Т., Дунчев В. П. Динамично поведение на права греда върху еластични опори под действие на движещ се товар – обобщение на уравнението на R. Willis. Известия на Технически университет Габрово 45 (2013) 3 - 10.
Издателство: Издателство "Васил Априлов" - ТУ-Габрово
Изд.год.: 2013
Вид: Научна публикация - Статия в бълг. списание

Публикация: №61 Максимов Й. Т., Дунчев В. П. Приложение на тригонометрични редове за моделиране на еластичната линия на права двуподпорна греда с ъглови еластични връзки. Известия на Технически университет Габрово 45 (2013) 11 - 16.
Издателство: Издателство "Васил Априлов" - ТУ-Габрово
Изд.год.: 2013
Вид: Научна публикация - Статия в бълг. списание

Публикация: №62 В. П. Дунчев, Крайно - елементен подход за моделиране коравината на ъгловите връзки на главната греда на мостов кран. Известия на Технически университет – Габрово, 45, (2013), 33 - 37.
Издателство: Известия на Технически университет – Габрово
Изд.год.: 2013
Вид: Научна публикация - Статия в бълг. списание

Публикация: №63 Maximov JT, Duncheva GV, Ganev N, Bakalova TN. The benefit from adequate finite element simulation of the cold hole expansion process. Engineering Failure Analysis 16(1) (2009) 503-511
Издателство: ELSEVIER
Изд.год.: 2009
Вид: Научна публикация - Статия в чужд. списание
Абстракт: The article presents outcomes from finite element and X-ray diffraction analyses of the cold hole expansion process fulfilled by means of solid mandrel gradually passing through the hole. Regardless of the manner of accomplishing – split sleeve; split mandrel; with a mating tapered split sleeve; spherical mandrelling – an axial gradient of the residual stresses is obtained due to the interaction between the layers caused by an axial force flow which passes through the mandrel, the workpiece and the support to forma closed circuit. To predict the fatigue life it is necessary to know the residual stresses on the entrance and the exit faces immediately to the hole periphery which are considered to be potential crack initiation sites. It has been proved that there are two key moments in the building of an adequate finite element model. The first is modeling of a realistic contact mandrel-workpiece with or without mediator and workpiece-support. The second is a suitable constitutive model of the workpiece material. Six hardening models of low-carbon steel obtained on the basis of a symmetric strain-controlled experiment and half-cycle test data from unidirectional tension experiment have been used consecutively in the finite element model of the process. On the basis of a comparison with experimental results obtained by means of an X-ray diffraction technique it has been established that the nonlinear kinematic hardening model obtained by a strain-controlled cyclic test to achieve a stabilized cycle secures finite element results close to the experimental ones. The chosen finite element model has been compared with simplified ones following the residual circumferential normal stress criterion and its advantages have been proved
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