1. Simulation-based algorithm for continuous improvement of enterprises performanceJ. Pervaz, Nemanja Sremčev, Branislav Stevanov, Leo Gusel, 2024, original scientific article Abstract: The printing company’s process performance depends on the possibility of providing requested products and managing the existing constraints of fixed machine layouts and high setup times between different products. Process inefficiencies caused by these factors reflect on throughput, production times, and resource utilization. The changes that improve one part of the production system usually affect other parts, needing additional optimization, and it is very useful to test the feasibility of proposed solutions with simulation before implementation. This paper presents a new algorithm for continuous improvement of enterprises performance, combining the lean approach with cellular manufacturing, and simulation. The performance is observed in a way that a certain setup influences the system in its entirety, rather than on a specific part of that system. The results are presented through models developed within the production optimization phase, representing various ways in which the continuous improvement algorithm can unfold. Each of them comes with its advantages and disadvantages, all intending to create more efficient production processes that generate less production waste.
Keywords: printing process, lean management, product groups, manufacturing cells, simulation, continuous improvement
Published in DKUM: 10.03.2025; Views: 0; Downloads: 4
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2. Sodobni inženirski materialiIvan Anžel, Franc Zupanič, Mihael Brunčko, 2025, other educational material Abstract: Skripta, Sodobni inženirski materiali je kot temeljno študijsko gradivo namenjeno pervenstveno študentom 2. stopnje študijskih programov Strojništva, Gospodarskega inženirstva, Mehatronike in študentom Inženirsko oblikovanja izdelkov. Skripta je sestavljena iz treh poglavij: (i) Zgradba in izbira inženirskih materialov; (ii) Lastnosti inženirskih materialov; (iii) Primeri sodobnih inženirskih materialov. V prvem poglavju je obravnavana zgradba kovinskih, keramičnih, polimernih in kompozitnih materialov ter predstavljeni so kriteriji, ki omogočajo inženirjem glede na želeno kombinacijo lastnosti materialov, njihovo ustrezno izbiro za določeno aplikacijo. Drugo poglavje obravnava lastnosti sodobnih inženirskih materialov s poudarkom na poglobljenem študiju razlage korelacij med zgradbo, mikrostrukturo in lastnostmi. V zadnjem najobsežnejšem poglavju so predstavljeni izbrani primeri sodobnih inženirskih materialov, katerih uporaba e v industrijski praksi dandanes zelo aktualna. Če naštejemo samo najbolj zanimive: disperzijsko utrjeni materiali, spominske zlitine, konstrukcijska keramika, materiali za shranjevanje vodika, hitrostrjeni kovinski materiali, sodobne aluminijeve zlitine, biopolimeri in še mnogi drugi.
Keywords: sodobni inženirski materiali, zgradba, izbira materialov, mikrostruktura, lastnosti
Published in DKUM: 27.02.2025; Views: 0; Downloads: 752
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3. Comparative analysis of a 3D printed polymer bonded magnet composed of a TPU-PA12 matrix and Nd-Fe-B atomised powder and melt spun flakes respectivelyGranit Hajra, Mihael Brunčko, Leo Gusel, Ivan Anžel, 2025, original scientific article Abstract: The present study reports the development of new polymer bonded magnet containing a Thermoplastic Polyurethane (TPU) – Nylon (PA12) blend as the matrix material and Nd-Fe-B magnetic particles. Two composite materials were explored: one using Nd-Fe-B atomised spherical powder (ASP) and another incorporating Nd-Fe-B melt-spun flakes (MSF). The filaments were formulated by blending TPU, PA12, and one of selected type of Nd-Fe-B particles using a mixing device. The ASP and the MSF were integrated into the matrix via a precise compounding process and 3D printing was used to produce the testing specimens. The preliminary findings indicate that both formulations exhibited promising magnetic properties while maintaining the mechanical characteristics of TPU and PA12. The atomised spherical powder formulation demonstrated worse magnetic behaviour compared to the melt-spun flake formulation. ASP particles enable better fluidity of the composite material during 3D printing. However, the close-packed arrangement of these particles is the cause of much higher porosity and consequently the poorer mechanical and magnetic properties. Optimization of the processing parameters showed significant influence on the final magnetic performance and structural integrity of the printed specimens.
Keywords: bonded magnets, Nd-Fe-B melt spun flakes, Nd-Fe-B atomised powders, material extrusion, additive manufacturing, fused specimen fabrication
Published in DKUM: 08.01.2025; Views: 0; Downloads: 9
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4. Reduction of surface defects by optimization of casting speed using genetic programming : an industrial case studyMiha Kovačič, Uroš Župerl, Leo Gusel, Miran Brezočnik, 2023, original scientific article Abstract: Štore Steel Ltd. produces more than 200 different types of steel with a continuous caster installed in 2016. Several defects, mostly related to thermomechanical behaviour in the mould, originate from the continuous casting process. The same casting speed of 1.6 m/min was used for all steel grades. In May 2023, a project was launched to adjust the casting speed according to the casting temperature. This adjustment included the steel grades with the highest number of surface defects and different carbon content: 16MnCrS5, C22, 30MnVS5, and 46MnVS5. For every 10 °C deviation from the prescribed casting temperature, the speed was changed by 0.02 m/min. During the 2-month period, the ratio of rolled bars with detected surface defects (inspected by an automatic control line) decreased for the mentioned steel grades. The decreases were from 11.27 % to 7.93 %, from 12.73 % to 4.11 %, from 16.28 % to 13.40 %, and from 25.52 % to 16.99 % for 16MnCrS5, C22, 30MnVS5, and 46MnVS5, respectively. Based on the collected chemical composition and casting parameters from these two months, models were obtained using linear regression and genetic programming. These models predict the ratio of rolled bars with detected surface defects and the length of detected surface defects. According to the modelling results, the ratio of rolled bars with detected surface defects and the length of detected surface defects could be minimally reduced by 14 % and 189 %, respectively, using casting speed adjustments. A similar result was achieved from July to November 2023 by adjusting the casting speed for the other 27 types of steel. The same was predicted with the already obtained models. Genetic programming outperformed linear regression.
Keywords: continuous casting of steel, surface defects, automatic control, machine learning, modelling, optimisation, prediction, linear regression, genetic programming
Published in DKUM: 25.03.2024; Views: 284; Downloads: 19
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5. Evaluation of the impact and fracture toughness of a nanostructured bainitic steel with low retained austenite contentMihael Brunčko, Peter Kirbiš, Ivan Anžel, Leo Gusel, Darja Feizpour, Tomaž Irgolič, Tomaž Vuherer, 2023, original scientific article Abstract: The impact and fracture toughness of a nanostructured, kinetically activated bainitic steel was determined using Standard methods. Prior to testing, the steel was quenched in oil and aged naturally for a period of 10 days in order to obtain a fully bainitic microstructure with a retained austenite content below 1%, resulting in a high hardness of 62HRC. The high hardness originated from the very fine microstructure of bainitic ferrite plates formed at low temperatures. It was determined that the impact toughness of the steel in the fully aged condition improved remarkably, whereas the fracture toughness was in line with expectations based on the extrapolated data available in the literature. This suggests that a very fine microstructure is most beneficial to rapid loading conditions, whereas material flaws such as coarse nitrides and non-metallic inclusions are the major limitation for obtaining a high fracture toughness.
Keywords: evaluation of fracture toughness, impact toughness, nanostructured bainite, natural aging, low retained austenite content, kinetically activated bainite KAB
Published in DKUM: 16.02.2024; Views: 390; Downloads: 29
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6. Optimizacija procesnih parametrov servo stiskalnice pri postopku preoblikovanja materiala : magistrsko deloMatej Pirc, 2023, master's thesis Abstract: Magistrska naloga je bila izdelana v sodelovanju z podjetjem TPV Automotive d. o. o., ki je razvojni dobavitelj v avtomobilski industriji. Izdelke izdelujejo z različnimi postopki, medtem ko je bil predmet magistrske naloge postopek preoblikovanja globoki vlek z uporabo servo stiskalnice Fagor TSED4-3000-7000-2500. V sklopu magistrske naloge sem optimiziral procesne parametre servo stiskalnice z uporabo programskega paketa Syncro. Omenjeni program omogoča izdelavo poljubnega hitrostnega profila stiskalnice ob upoštevanju fizičnih omejitev stiskalnice in tehnoloških omejitev izdelka. Hitrostni profil sem optimiziral za štiri različna orodja, katerih produktivnost sem povečal v povprečju za 38%.
Keywords: Stroji za preoblikovanje, servo stiskalnica, tehnološki postopki preoblikovanja, globoki vlek, procesni parametri, optimizacija
Published in DKUM: 07.12.2023; Views: 404; Downloads: 0
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7. Optimizacija proizvodnje nosilcev prikolice s prebijalnim cnc strojem euromac mtx flex : diplomsko deloUroš Tušek, 2020, undergraduate thesis Abstract: V diplomskem delu je predstavljena vpeljava modernega prebijalnega CNC stroja Euromac v serijsko proizvodnjo nosilcev za izdelavo avtomobilskih prikolic. Predstavljena je vloga novega stroja v obstoječem proizvodnem procesu. Delo zajema podatke o stroju, predstavitev več funkcijskega orodnega sistema in 2D programiranje v programskem okolju TopPunch. Izvedeni so različni primeri izdelave in obdelave nosilcev prikolice. Na ta način so prikazane razne zmogljivosti stroja. Na podlagi zbranih podatkov sem analiziral prednosti novega CNC stroja na področju materialov, optimizacije, natančnosti in kakovosti. Predstavljena je primerjava zbranih podatkov s podatki enakih nosilcev, pridobljenih na starejšem CNC stroju in izvedena krajša analiza stroškov. Praktični del diplomskega dela sem izvedel v podjetju TPV Prikolice.
Keywords: proizvodnja, prebijanje, prebijalni stroj, orodje, programiranje, materiali
Published in DKUM: 01.10.2020; Views: 796; Downloads: 67
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8. Vpliv radija pestiča in širine materiala na elastično poravnavanje pri procesu upogibanja : diplomsko deloJure Vezonik, 2019, undergraduate thesis Abstract: Diplomska naloga opisuje proces upogibanja, ki velja za enega najbolj razširjenih tehnoloških postopkov za preoblikovanje pločevine. Namen diplomskega dela je z eksperimentalnim delom ugotoviti, kako nekateri geometrijski parametri vplivajo na elastično poravnavo pri upogibanju po razbremenitvi. Rezultati eksperimentalnega dela, ki so prikazani v obliki grafov in preglednic ter so primerjani z analitičnimi preračuni, so pokazali, da je vpliv radija pestiča na velikost elastične poravnave zelo velik, medtem ko širina komada nima pomembnejšega vpliva na elastično poravnavanje.
Keywords: upogibanje pločevine, radij pestiča, elastična poravnava, kot zravnanja
Published in DKUM: 01.10.2019; Views: 1077; Downloads: 162
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10. Optimizacija menjave orodij v podjetju unior d.d.Martin Kočnik, 2018, undergraduate thesis Abstract: V današnjih časih so potrebe na tržišču kovanih izdelkov vsak dan večje. Zaradi tega vsako podjetje želi zadovoljiti potrebe kupca in mu zagotavljati najvišje možne kapacitete v najkrajšem času. S pomočjo nenehnega prilagajanja in optimizacije proizvodnje je mogoče skrajšati nepotrebne zastoje, povečati produktivnost ter izboljšati kvaliteto proizvodov.
Diplomsko delo obravnava optimizacijo časa menjave orodja na kovaški liniji v podjetju Unior d. d. in uvedbo hitrih menjav orodij s pomočjo metode SMED. Menjavo na kovaški liniji sem s pomočjo posnetega stanja menjave analiziral in se odločal o najbolj smiselnih popravkih procesa, ki privedejo do občutnega skrajšanja časa menjave orodij. Te optimizacijske spremembe so bile uvedene na kovaški liniji tudi v praksi. V nalogi je podana tudi podrobna primerjava med prejšnjim in izboljšanim (optimiziranim) stanjem procesa menjave orodja na kovaški liniji.
Keywords: Preoblikovanje, kovaška linija, menjava orodja, metoda SMED, optimizacija
Published in DKUM: 21.09.2018; Views: 1941; Downloads: 197
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