Modelling of Dross Height in Plasma Jet Cutting Process of Aluminium Alloy 5083 Using Fuzzy Logic Technique

Dross height is an important cut quality characteristic in plasma jet cutting process. It can be defined as molten metal blown from the cutting zone and localized on the bottom of the metal sheet. In each plasma jet cutting process, it is important to obtain dross free cuts. Aluminium is as material very present in shipbuilding and metal industry and because of that very usually cut by plasma jet. Because of high heat and electrical conductivity of aluminium, plasma jet cutting is followed by insecurity about process parameters settings that lead to optimal cut quality characteristics. The aim of this paper is to develop a fuzzy logic model that predicts the influence of variable process parameters on dross height in plasma jet cutting of aluminium alloy 5083. Experiments were performed according to Taguchi L27 orthogonal array by varying cutting speed, arc current and cutting height as input process parameters. Fuzzy logic model was defined using Mamdani inference system. This model was used to investigate effects of variable process parameters on dross height response. In order to analyse interaction effects of plasma jet cutting process parameters on dross formation 3D surface and contour plots were generated. The analysis revealed that the cutting speed has the most significant effect followed by arc current and cutting height. Obtained results of this research indicate that artificial intelligence technique, fuzzy logic, can be effectively used for modelling and prediction of dross formation in plasma jet cutting process of aluminium alloy

Modelling of Kerf Width in Plasma Jet Metal Cutting Process using ANN Approach

In this paper Artificial Neural Network (ANN) model was developed for prediction of kerf width in plasma jet metal cutting process. Process parameters whose influence was analyzed are cutting height, cutting speed and arc current. An L18 (21x37) Taguchi orthogonal array experiment was conducted on aluminium sheet of 3 mm thickness. Using the experimental data a feed – forward backpropagation artificial neural network model was developed. After the prediction accuracy of the developed model was verified, the model was used to generate plots that show influence of process parameters and their interactions on analzyed kerf width and to get conlusions about process parameters values that lead to minimal kerf width

Multi-Response Optimization in MQLC Machining Process of Steel St50-2 Using Grey-Fuzzy Technique

In this paper MQLC turning process of steel St 50-2 is presented. Experimentations were performed using Taguchi L9 orthogonal array by varying two process parameters such as oil and water quantity while other parameters such as cutting speed, feed rate and depth of cut were kept constant. Process responses that were analyzed in this paper are surface roughness Ra and resultant cutting force Frez. In order to quantify significance of each process parameter on analyzed response ANOVA was conducted. Fuzzy logic modelling technique was used to describe the effects of process parameters and to create response surface plots. Finally, in order to find out process parameters values that lead simultaneously to optimal surface roughness and resultant cutting force, multi-objective optimization of process responses was conducted by using grey relational analysis (GRA) combined with fuzzy logic technique

Application of AHP, Fuzzy AHP and PROMETHEE Method in Solving Additive Manufacturing Process Selection Problem

Additive manufacturing is a technology of making a three-dimesional solid object of any shape from a digital model. Today on the global market exist various additive manufacturing processes. All of these processes build parts by applying material layer by layer. In a wide range of different processes there is a problem of selecting an adequate process for a user or company interested in additive manufacturing technology. Solving of such a problem is possible by using multicriteria decision methods which result in ranking of alternatives. Thus the user or company can easily select one of the available additive manufacturing processes. In this paper basic methodology of application of three different multicriteria decision methods in solving the mentioned problem was shown. These methods are: Analytic hierarchy process (AHP), Fuzzy AHP and Preference ranking organization method (PROMETHEE). Available alternatives are processes: 3D printing, Fused Deposition Modeling, Selective Laser Sintering and Photopolymer Jetting

Influence of the plasma jet cutting process factors on the cut quality of aluminium alloys

Rezanje plazmenim mlazom je nekonvencionalni termoelektrični postupak uvelike prisutan u metaloprerađivačkoj industriji i brodogradnji. Plazmeni mlaz nastaje disocijacijom i ionizacijom plazmenog plina, te posjeduje visoku gustoću energije i visoku temperaturu, zbog čega je sposoban rezati različite vrste metala širokog raspona debljina. Aluminij kao materijal karakterizira manja gustoća, veća toplinska i električna vodljivost te veća otpornost prema koroziji, zbog čega se naročito koristi u brodogradnji te za izradu različitih konstrukcija. Zbog takvih svojstava prilikom njegovog rezanja plazmenim mlazom prisutna je određena doza nesigurnosti kod definiranja vrijednosti faktora procesa i uvjeta postizanja što je moguće bolje kvalitete reza. U ovom radu pristupilo se istraživanju rezljivosti aluminijske legure AlMg4.5Mn (EN AW 5083) plazmenim mlazom. Eksperimentalno istraživanje je provedeno na tri različite debljine lima. Za svaku debljinu lima u okviru analiziranog eksperimentalnog hiperprostora definirana su ograničenja tj. kombinacije faktora procesa kojima nije moguće rezanje. Primjenom različitih metoda modeliranja, umjetnih neuronskih mreža, fuzzy logike i regresije opisan je utjecaj promjenjivih faktora procesa rezanja na odzivne karakteristike kvalitete reza, te su stvoreni preduvjeti za kreiranje ekspertnog sustava koji će se moći nadopunjavati dodatnim eksperimentalnim rezultatima. Primjenom različitih metoda optimizacije: Taguchi metode, analize poželjnosti i metaheurističke optimizacije genetskim algoritmom provedena je jednociljna i višeciljna optimizacija funkcija cilja, te je deteterminirano optimalno područje rezanja s obzirom na postizanje maksimalne moguće kvalitete reza i proizvodnosti. Ostvareni rezultati predstavljaju kvalitetnu osnovu za upravljanje i daljnje unaprjeđenje procesa rezanja.Plasma jet cutting is a nonconventional thermoelectric process widely used in metal processing and shipbuilding industry. Plasma jet is generated by dissociation and ionization of plasma gas and it is capable of cutting different types of metals with wide range of thicknesses. As a material, aluminium is known for its relatively low density, high thermo and electrical conductivity with significant corrosion resistance. Therefore, it has been particularly used in shipbuilding industry, as well as in designing various types of constructions. Due to their properties, plasma jet cutting of aluminium alloys raises a certain dose of insecurity regarding process factors value definition, as well as achieving optimal cut quality. In this paper, a research of plasma jet cutting suitability of aluminium alloy AlMg4.5Mn (EN AW 5083) was conducted. Experimental work was carried out on three different sheet thicknesses. For each sheet thickness, in the frame of experimental hyperspace, constraints i.e. process factors combinations which do not lead to cuts were identified. Using different modeling methods: artificial neural networks, fuzzy logic and regression, influence of variable cutting process factors on output cut quality characteristics was described. Moreover, preconditions for creating expert system which could be supplemented with additional experimental results were realized.. Using different optimization methods: Taguchi method, desirability analysis and metaheuristic optimization by genetic algorithm, one objective and multiobjective optimization were conducted. Achieving of maximal possible cut quality as well as productivity, was considered also through the use of these methods in order to determine optimal cutting area. Obtained results represent good foundation for control and further improvement of cutting proces

Influence of the plasma jet cutting process factors on the cut quality of aluminium alloys

Rezanje plazmenim mlazom je nekonvencionalni termoelektrični postupak uvelike prisutan u metaloprerađivačkoj industriji i brodogradnji. Plazmeni mlaz nastaje disocijacijom i ionizacijom plazmenog plina, te posjeduje visoku gustoću energije i visoku temperaturu, zbog čega je sposoban rezati različite vrste metala širokog raspona debljina. Aluminij kao materijal karakterizira manja gustoća, veća toplinska i električna vodljivost te veća otpornost prema koroziji, zbog čega se naročito koristi u brodogradnji te za izradu različitih konstrukcija. Zbog takvih svojstava prilikom njegovog rezanja plazmenim mlazom prisutna je određena doza nesigurnosti kod definiranja vrijednosti faktora procesa i uvjeta postizanja što je moguće bolje kvalitete reza. U ovom radu pristupilo se istraživanju rezljivosti aluminijske legure AlMg4.5Mn (EN AW 5083) plazmenim mlazom. Eksperimentalno istraživanje je provedeno na tri različite debljine lima. Za svaku debljinu lima u okviru analiziranog eksperimentalnog hiperprostora definirana su ograničenja tj. kombinacije faktora procesa kojima nije moguće rezanje. Primjenom različitih metoda modeliranja, umjetnih neuronskih mreža, fuzzy logike i regresije opisan je utjecaj promjenjivih faktora procesa rezanja na odzivne karakteristike kvalitete reza, te su stvoreni preduvjeti za kreiranje ekspertnog sustava koji će se moći nadopunjavati dodatnim eksperimentalnim rezultatima. Primjenom različitih metoda optimizacije: Taguchi metode, analize poželjnosti i metaheurističke optimizacije genetskim algoritmom provedena je jednociljna i višeciljna optimizacija funkcija cilja, te je deteterminirano optimalno područje rezanja s obzirom na postizanje maksimalne moguće kvalitete reza i proizvodnosti. Ostvareni rezultati predstavljaju kvalitetnu osnovu za upravljanje i daljnje unaprjeđenje procesa rezanja.Plasma jet cutting is a nonconventional thermoelectric process widely used in metal processing and shipbuilding industry. Plasma jet is generated by dissociation and ionization of plasma gas and it is capable of cutting different types of metals with wide range of thicknesses. As a material, aluminium is known for its relatively low density, high thermo and electrical conductivity with significant corrosion resistance. Therefore, it has been particularly used in shipbuilding industry, as well as in designing various types of constructions. Due to their properties, plasma jet cutting of aluminium alloys raises a certain dose of insecurity regarding process factors value definition, as well as achieving optimal cut quality. In this paper, a research of plasma jet cutting suitability of aluminium alloy AlMg4.5Mn (EN AW 5083) was conducted. Experimental work was carried out on three different sheet thicknesses. For each sheet thickness, in the frame of experimental hyperspace, constraints i.e. process factors combinations which do not lead to cuts were identified. Using different modeling methods: artificial neural networks, fuzzy logic and regression, influence of variable cutting process factors on output cut quality characteristics was described. Moreover, preconditions for creating expert system which could be supplemented with additional experimental results were realized.. Using different optimization methods: Taguchi method, desirability analysis and metaheuristic optimization by genetic algorithm, one objective and multiobjective optimization were conducted. Achieving of maximal possible cut quality as well as productivity, was considered also through the use of these methods in order to determine optimal cutting area. Obtained results represent good foundation for control and further improvement of cutting proces

Fitness Training in Football : Undergraduate Thesis

Cilj ovoga rada je objasniti važnost kondicijske pripreme u nogometu. Ona predstavlja osnovu nogometnog treninga. U radu su prikazana dosadašnja istraživanja, analiza nogometne igre te struktura kondicijskog treninga. Analizom nogometne igre dolazimo do podataka o opterećenjima s kojima se susreću igrači na treninzima i utakmicama, a da bi igrači bili sposobni odgovoriti svim zahtjevima nogometne igre moraju posjedovati odgovarajuću razinu fizičke pripreme.The aim of this paper is to explain the importance of strength and conditioning in football. It is the basis of football training. The paper presents previous research, analysis of football games and the structure of strength and conditioning. The analysis of football games leads to data on the loads that players face in training and matches, and in order for players to be able to meet all the requirements of football games, they must have an appropriate level of strength and conditioning

Analysis and Application of Data Collected by Notational Analysis in the LongoMatch Program : Undergraduate Thesis

U ovome je radu objašnjena obrada i primjena podataka prikupljenih notacijskom analizom. Podaci dobiveni tom metodom daju povratnu informaciju trenerima, analitičarima i samim igračima na temelju koje mogu planirati, programirati, raditi na slabijim točkama te provoditi trenažni proces s ciljem unaprjeđenja pojedinca i/ili cijele ekipe. Jedan od načina prikupljanja podataka je računalni program LongoMatch koji omogućava analitičarima/trenerima dobivanje podataka odabranih pokazatelja situacijske efikasnosti. Dakle, ukratko je objašnjen pojam i primjer notacijske analize u programu LongoMatch te je provedeno istraživanje u kojem je cilj bio dobiti uvid u situacijsku efikasnost na domaćim i gostujućim utakmicama kadetske ekipe nogometnog kluba Hajduk. U istraživanju je sudjelovalo 22 igrača koji su odigrali 16 utakmica prve Hrvatske nogometne lige. Promatrano je 10 varijabli čiji su rezultati dobiveni notacijskom analizom. Istraživanjem nije utvrđeno postojanje statistički značajne razlike između promatranih varijabli situacijske efikasnosti na utakmicama odigranim na domaćem i gostujućim terenima te između igrača iz prvog sastava i rezervnih igrača.This paper explains the processing and application of data collected through notational analysis. The data obtained by this method provide feedback to coaches, analysts and the players themselves, on the basis of which they can plan, program, work on weak points and implement the training process with the aim of improving the individual and/or the entire team. One of the methods of data collection is the computer program LongoMatch, which enables analysts/coaches to obtain data on selected indicators of situational efficiency. So, the term and example of notational analysis in the LongoMatch program was briefly explained, and research was conducted in which the goal was to gain insight into the situational efficiency at home and away matches of the cadet team of the Hajduk football club. In this research participated 22 players who played 16 matches of the first Croatian football league. There were observed 10 variables, the results of which were obtained by notational analysis. The research did not establish the existence of a statistically significant difference in the observed variables of situational efficiency in matches played on home and away grounds and between players from the first team and reserve players

Fitness Training in Football : Undergraduate Thesis

Cilj ovoga rada je objasniti važnost kondicijske pripreme u nogometu. Ona predstavlja osnovu nogometnog treninga. U radu su prikazana dosadašnja istraživanja, analiza nogometne igre te struktura kondicijskog treninga. Analizom nogometne igre dolazimo do podataka o opterećenjima s kojima se susreću igrači na treninzima i utakmicama, a da bi igrači bili sposobni odgovoriti svim zahtjevima nogometne igre moraju posjedovati odgovarajuću razinu fizičke pripreme.The aim of this paper is to explain the importance of strength and conditioning in football. It is the basis of football training. The paper presents previous research, analysis of football games and the structure of strength and conditioning. The analysis of football games leads to data on the loads that players face in training and matches, and in order for players to be able to meet all the requirements of football games, they must have an appropriate level of strength and conditioning

Analysis and Application of Data Collected by Notational Analysis in the LongoMatch Program : Undergraduate Thesis

U ovome je radu objašnjena obrada i primjena podataka prikupljenih notacijskom analizom. Podaci dobiveni tom metodom daju povratnu informaciju trenerima, analitičarima i samim igračima na temelju koje mogu planirati, programirati, raditi na slabijim točkama te provoditi trenažni proces s ciljem unaprjeđenja pojedinca i/ili cijele ekipe. Jedan od načina prikupljanja podataka je računalni program LongoMatch koji omogućava analitičarima/trenerima dobivanje podataka odabranih pokazatelja situacijske efikasnosti. Dakle, ukratko je objašnjen pojam i primjer notacijske analize u programu LongoMatch te je provedeno istraživanje u kojem je cilj bio dobiti uvid u situacijsku efikasnost na domaćim i gostujućim utakmicama kadetske ekipe nogometnog kluba Hajduk. U istraživanju je sudjelovalo 22 igrača koji su odigrali 16 utakmica prve Hrvatske nogometne lige. Promatrano je 10 varijabli čiji su rezultati dobiveni notacijskom analizom. Istraživanjem nije utvrđeno postojanje statistički značajne razlike između promatranih varijabli situacijske efikasnosti na utakmicama odigranim na domaćem i gostujućim terenima te između igrača iz prvog sastava i rezervnih igrača.This paper explains the processing and application of data collected through notational analysis. The data obtained by this method provide feedback to coaches, analysts and the players themselves, on the basis of which they can plan, program, work on weak points and implement the training process with the aim of improving the individual and/or the entire team. One of the methods of data collection is the computer program LongoMatch, which enables analysts/coaches to obtain data on selected indicators of situational efficiency. So, the term and example of notational analysis in the LongoMatch program was briefly explained, and research was conducted in which the goal was to gain insight into the situational efficiency at home and away matches of the cadet team of the Hajduk football club. In this research participated 22 players who played 16 matches of the first Croatian football league. There were observed 10 variables, the results of which were obtained by notational analysis. The research did not establish the existence of a statistically significant difference in the observed variables of situational efficiency in matches played on home and away grounds and between players from the first team and reserve players