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1.
Istosmerno iztiskovanje profilov iz Aluminijevih zlitin
Boštjan Povh, 2016, undergraduate thesis

Abstract: Diplomsko delo zajema osnove iztiskovanja aluminijevih zlitin, predstavitev postopkov iztiskovanja ter opis strojev in orodij, ki se za to uporabljajo. Diplomsko delo sem opravljal s pomočjo podjetja Impol, d. o. o., iz Slovenske Bistrice, ki se ukvarja na splošno z aluminijem in z izdelavo raznih izdelkov, kot so valjani traki, cevi, palice, profili, odkovki. Podjetje Impol PCP – Profili za izdelavo iztisnjenih izdelkov uporablja postopek vročega istosmernega iztiskovanja. S tem postopkom bo iztisnjen nov profil za praktični del naloge, ki zajema opis in potek izdelave novega aluminijevega profila. Postopek se bo izvajal na stroju stiskalnica 28 MN, ki se nahaja v tem proizvodnem procesu.
Keywords: iztiskovanje, iztiskovalni postopki, stroji in orodja za iztiskovanje, aluminijasti profili
Published: 19.03.2021; Views: 167; Downloads: 25
.pdf Full text (4,38 MB)

2.
Razvoj sistema za zagotavljanje načrtovanega položaja kolčnih endoprotez s pacientu prilagojenimi medicinskimi pripomočki
Urška Kostevšek Šegula, 2020, doctoral dissertation

Abstract: Popolna zamenjava kolka (ang. Total Hip Arthroplasty (THA)) je poseg, v katerem poškodovani kolk zamenjajo z notranjo sklepno protezo (endoprotezo). Če želijo zagotoviti pravilno in dolgoročno delovanje endoproteze, je treba oba dela vsadka pravilno orientirati v medeničnem prostoru. Slednjemu je namenjeno pred-operativno načrtovanje. Pred-operativno načrtovanje v ustaljeni kirurški praksi še vedno izvajajo na dvo-razsežnih rentgenskih slikah. 2D načrtovanje je načrtovanje na projekciji kosti, ki le stežka da oprijemljiv občutek trirazsežnosti defekta. Za ponovno vzpostavitev biomehanike kolčnega sklepa pri velikih defektih morajo ortopedski kirurgi defekt zapolniti s sestavljanjem standardnih komponent, ki se po podatkih iz obstoječih registrov ne obnesejo najbolje. Zaradi slednjega smo v sklopu te doktorske disertacije razvili in vzpostavili sistem načrtovanja in izdelave pacientu prilagojenih medicinskih pripomočkov. Razvili in izdelali smo sistem načrtovanja vsadka in vodil, ki so bila sredstvo za prenos načrtovanih parametrov v operativno okolje. Vsadek je oblikovno zapolnil defekt in je bil za vsakega pacienta posebej prilagojen glede na anatomske parametre njegove medenice, obliko defekta in razpoložljivo kost. Sistem smo klinično preizkusili na pacientih, ki so bili načrtovani za poseg zamenjave kolčne endoproteze in so imeli veliko izgubo kosti. Za vsakega v raziskavo vključenega pacienta smo na podlagi posnetkov medenice z računalniškim tomografom (CT) izvedli rekonstrukcijo tri-razsežnega modela, tri-razsežno načrtovanje posega, skonstruirali in izdelali sklope pacientu prilagojenih medicinskih pripomočkov, izdelali vso potrebno dokumentacijo, dokumentirali vsak operativni poseg in rezultate na podlagi po-operativnega CT posnetka analizirali. V sklopu doktorske disertacije smo izdelali 10 sistemov za 10 pacientov. Vsi klinični preizkusi sistema so bili uspešni, saj smo pri vseh pacientih dosegli stabilnost, trdnost in načrtovano biomehaniko sklepa. Povprečna razlika med načrtovanimi in pooperativnimi vrednostmi je glede na po-operativne CT posnetke vseh 10 bolnikov znašala 6 mm in 10°. Slednje je območje dosegljivih natančnosti zagotavljanja načrtovanega položaja kolčnih endoprotez s pacientu prilagojenimi medicinskimi pripomočki.
Keywords: trirazsežno načrtovanje, individualni medicinski pripomočki, dodajalna izdelava, operacija kolka
Published: 16.10.2020; Views: 339; Downloads: 45
.pdf Full text (3,10 MB)

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Priprava orodij za hladno preoblikovanje v velikoserijski proizvodnji
Matej Budja, 2018, master's thesis

Abstract: V podjetjih s proizvodnjo velikoserijskih izdelkov s procesom hladnega preoblikovanja je treba vsako posamezno »orodje za hladno preoblikovanje« (v nadaljnjem tekstu »orodje«) pripraviti na delovanje pazljivo, natančno in hkrati hitro. Z neupoštevanjem konstrukcijskih in organizacijskih določil ter pomanjkanjem znanja s področja priprave orodja lahko pride do problemov in poškodb delavca ter orodja v orodjarni ali pri obratovanju na stroju. Zaradi teh dejavnikov posledično sledijo zastoji v procesu, ker je treba orodje z delovnega mesta odpeljati v orodjarno ter ugotoviti in odpraviti vzrok napake. Takšni zastoji pa podjetju predstavljajo nepotrebni strošek. V času preizkušanja in serijske uporabe je treba konstrukcijsko izvedbo orodij tudi izboljševati. Te probleme je potrebno reševati sproti in dosledno, saj je vsakemu podjetju v interesu, da procesi v proizvodnji zaradi tega ne zastajajo.
Keywords: Orodje, hladno preoblikovanje, orodjarna, stiskalnica, kovanje, dimenzioniranje, navodila.
Published: 04.10.2018; Views: 613; Downloads: 110
.pdf Full text (7,01 MB)

5.
Prediction of technological parameters of sheet metal bending in two stages using feed-forward neural network
Jernej Šenveter, Jože Balič, Mirko Ficko, Simon Klančnik, 2016, original scientific article

Abstract: This paper describes sheet metal bending in two stages as well as predicting and testing of the final bend angle by means of a feed-forward neural network. The primary objective was to research the technological parameters of bending sheet metal in two stages and to develop an intelligent method that would enable the predicting of those technological parameters. The process of bending sheet metal in two stages is presented by demonstrating the various technological parameters and the test tool used to carry out tests and measurements. The results of the tests and measurements were of decisive guidance in the evaluation of individual technological parameters. Developed method for prediction of the final bend angle is based on a feed-forward neural network that receives signals at the input level. These signals then travel through the hidden level to the output level, where the responses to input signals are received. The input to the neural network is composed of data that affect the selection of the final bend angle. Only five different inputs are used for the total neural network. By choosing the desired final bend angle by means of the trained neural network, bending sheet metal in two stages is optimised and made more efficient.
Keywords: bending in two stages, intelligent system, neural network, prediction of the final bend angle
Published: 12.07.2017; Views: 614; Downloads: 371
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6.
Prediction of dimensional deviation of workpiece using regression, ANN and PSO models in turning operation
David Močnik, Matej Paulič, Simon Klančnik, Jože Balič, 2014, original scientific article

Abstract: As manufacturing companies pursue higher-quality products, they spend much of their efforts monitoring and controlling dimensional accuracy. In the present work for dimensional deviation prediction of workpiece in turning 11SMn30 steel, the conventional deterministic approach, such as multiple linear regression and two artificial intelligence techniques, back-propagation feed-forward artificial neural network (ANN) and particle swarm optimization (PSO) have been used. Spindle speed, feed rate, depth of cut, pressure of cooling lubrication fluid and number of produced parts were taken as input parameters and dimensional deviation of workpiece as an output parameter. Significance of a single parameter and their interactive influences on dimensional deviation were statistically analysed and values predicted from regression, ANN and PSO models were compared with experimental results to estimate prediction accuracy. A predictive PSO based model showed better predictions than two remaining models. However, all three models can be used for the prediction of dimensional deviation in turning.
Keywords: artificial neural network, dimensional dviation, particle swarm optimization, regression
Published: 12.07.2017; Views: 558; Downloads: 111
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7.
Intelligent system for prediction of mechanical properties of material based on metallographic images
Matej Paulič, David Močnik, Mirko Ficko, Jože Balič, Tomaž Irgolič, Simon Klančnik, 2015, original scientific article

Abstract: This article presents developed intelligent system for prediction of mechanical properties of material based on metallographic images. The system is composed of two modules. The first module of the system is an algorithm for features extraction from metallographic images. The first algorithm reads metallographic image, which was obtained by microscope, followed by image features extraction with developed algorithm and in the end algorithm calculates proportions of the material microstructure. In this research we need to determine proportions of graphite, ferrite and ausferrite from metallographic images as accurately as possible. The second module of the developed system is a system for prediction of mechanical properties of material. Prediction of mechanical properties of material was performed by feed-forward artificial neural network. As inputs into artificial neural network calculated proportions of graphite, ferrite and ausferrite were used, as targets for training mechanical properties of material were used. Training of artificial neural network was performed on quite small database, but with parameters changing we succeeded. Artificial neural network learned to such extent that the error was acceptable. With the oriented neural network we successfully predicted mechanical properties for excluded sample.
Keywords: artificial neural network, factor of phase coherence between the surfaces, fracture toughness, image processing, mechanical properties, metallographic image, ultimate tensile strength, yield strength
Published: 12.07.2017; Views: 747; Downloads: 344
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8.
Initial study of immersion thermal manikin development and its manufacture from solid blocks
Ivo Pahole, Bogdan Valentan, Daniela Zavec Pavlinič, Mirko Ficko, Jože Balič, 2015, original scientific article

Abstract: Article presents the development and manufacture of a new generation of thermal manikins that can be used for testing different personal protective equipment as used under extreme environmental conditions. The demonstrated steps from the initial idea towards the final product were taken with the help of modern CAD/CAM tools and CNC manufacturing procedures. This article also presents some of the problems that occurred and had to be solved during the designing, manufacturing and assembly of the thermal manikin. Keywords:
Keywords: extreme environment, personal protective equipment, safety, thermal manikin
Published: 12.07.2017; Views: 613; Downloads: 273
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9.
Prediction of the hardness of hardened specimens with a neural network
Matej Babič, Peter Kokol, Igor Belič, Peter Panjan, Miha Kovačič, Jože Balič, Timotej Verbovšek, 2014, original scientific article

Abstract: In this article we describe the methods of intelligent systems to predict the hardness of hardened specimens. We use the mathematical method of fractal geometry in laser techniques. To optimize the structure and properties of tool steel, it is necessary to take into account the effect of the self-organization of a dissipative structure with fractal properties at a load. Fractal material science researches the relation between the parameters of fractal structures and the dissipative properties of tool steel. This paper describes an application of the fractal dimension in the robot laser hardening of specimens. By using fractal dimensions, the changes in the structure can be determined because the fractal dimension is an indicator of the complexity of the sample forms. The tool steel was hardened with different speeds and at different temperatures. The effect of the parameters of robot cells on the material was better understood by researching the fractal dimensions of the microstructures of hardened specimens. With an intelligent system the productivity of the process of laser hardening was increased because the time of the process was decreased and the topographical property of the material was increased.
Keywords: fractal dimension, fractal geometry, neural network, prediction, hardness, steel, tool steel, laser
Published: 17.03.2017; Views: 955; Downloads: 80
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10.
Inteligentni sistem za večkriterijsko optimizacijo tehnološkega načrta dvoosnega struženja
Zlatko Botak, 2016, doctoral dissertation

Abstract: Obdelovalni proces je pod stalnim vplivom razvoja in posodabljanja komponent v sistemu stroj-orodje-obdelovanec. Bolj kot so poznana zapletena razmerja med vhodnimi in izhodnimi veličinami, uspešnejši je končni rezultat obdelave s tehničnega in ekonomskega vidika. Obdelava množice medsebojno odvisnih podatkov in omejitev v realnem procesu s klasičnimi metodami ni več primerna, temveč se za optimizacijo poskuša narediti model, ki vključuje določeno stopnjo umetne inteligence. V disertaciji je predstavljen model inteligentnega sistema za samodejno programiranje obdelave struženja na rotacijskih izdelkih. Sistem je zmožen na osnovi 3D-modela izdelka samostojno prepoznati izdelovalnost s postopkom dvoosnega struženja, določiti obdelovalna orodja, zaporedje obdelave, izvesti optimalizacijo in pripraviti NC-program. Nastali NC-program bo glede na izbrane kriterije optimalen glede na čas in učinkovitost obdelave. Razviti inteligentni sistem deluje popolnoma samostojno, brez posega izkušenega strokovnjaka v potek priprave tehnologije. Obdelava se sočasno optimalizira po več kriterijih, po odrezovalnem času, odvzemu materiala, strošku orodja in številu prehodov orodja. Kriteriji se merijo v različnih enotah in se pogosto medsebojno izključujejo, kar pomeni, da izboljšanje obdelave po enem kriteriju pripelje do poslabšanja po drugem. V sistem za samodejno programiranje obdelave je vključena metoda za večkriterijsko optimiranje, analitični hierarhični proces. Metoda temelji razčlenjevanju problema na več ravni, primerjavi kriterijev po parih, izračun vpliva posamezne alternative na končni cilj in preverjanje doslednosti. Rezultati so dodatno preverjeni z metodo za večkriterijsko odločanje ELECTRE II in programom SuperDecisions. Predstavljeni model se lahko uporabi za analizo in optimalizacijo realnih problemov obdelave s struženjem v praksi.
Keywords: inteligentni obdelovalni sistem, večkriterijska optimalizacija, NC-programiranje, analitični hierarhični proces, računalniška simulacija, struženje.
Published: 03.01.2017; Views: 1181; Downloads: 187
.pdf Full text (5,34 MB)

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