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The paper presents a numerical analysis, using the finite element method, for the case of static and dynamic loading of the upper carriage of the remote-controlled combat station, due to the recoil force generated by the operation of the integrated automatic grenade launcher 30mm M93. The paper describes the problem of integrating the BGA 30mm M93 automatic grenade launcher onto the combat platform, and based on the dimensions of the automatic launcher, modeling of the automatic launcher stand with cradle was carried out. As a result of the weapon dynamics equations and internal ballistics calculations, the pressure force of the gunpowder gases and the recoil force of the automatic grenade launcher were calculated. The paper also presents the results of the dynamic analysis of the finite element model of the upper gun carriage loaded with the obtained impulse recoil force for different elevation angles of the weapon.

This paper presents Taguchi optimization of bevel angle in plasma jet cutting process of aluminium alloy EN AW 5083. Experimentations for this paper were carried out on the basis of standard L27 Taguchi's orthogonal array in which three plasma jet cutting parameters such as cutting speed, arc current and cutting height were arranged at three levels. From the analysis of means, analysis of variance and two-way interactions plot, significant plasma jet cutting process parameters and optimal combination of their levels that lead to minimal bevel angle were identified. The results showed that all three process parameters significantly affect bevel angle response. The predicted response at optimal plasma jet cutting conditions has a good fit with result of bevel angle from observed experiment.

The plasma jet cutting process has a high potential for the machining of aluminium and its alloys. Aluminium is well known as a highly thermally conductive and sensitive material, and because of that there exist uncertainties in defining process parameters values that lead to the best possible cut quality characteristics. Due to that, comprehensive analysis of process responses as well as defining optimal cutting conditions is necessary. In this study, the effects of three main process parameters—cutting speed, arc current, and cutting height—on the cut quality responses: top kerf width, bevel angle, surface roughness Ra, Rz, and material removal rate were analyzed. Experimentations were conducted on aluminium EN AW-5083. In order to model relations between input parameters and process responses and to conduct their optimization, a novel hybrid approach of response surface methodology (RSM) combined with desirability analysis was presented. Prediction accuracy of developed responses regression models was proved by comparison between experimental and predicted data. Significance of process parameters and their interactions was checked by analysis of variance (ANOVA). Desirability analysis was found as an effective way to conduct multi-response optimization and to define optimal cutting area. Due to its simplicity, the novel presented approach was demonstrated as a useful tool to predict and optimize cut quality responses in plasma jet cutting process of aluminium alloy.

Mechanical tests were performed on samples prepared from the body and the neck of bottles made of seamless tube, steel 34CrMo4. Plastic material flow curves were taken from tensile tests on samples which were made from tubes and finished bottles. Deformation hardening intensity is calculated, and propensity towards brittle fracture is estimated on the basis of the ratio of total elongation and elongation at maximum load. Compared to the samples of quenched and tempered bottle body, quenched and tempered bottle neck samples indicate that characteristics of strength are almost unchanged with an increase in the minimum strain at the destruction from 12, 8 % to 15, 1 %. It was concluded that the results of the plastic material flow can serve as a preliminary indication of anomalies that could contribute to unsatisfactory results of the burst test.

The classic methods of demilitarization of ordnance are high-risk operations, primarily for working personnel and operators, and then for the entire pyrotechnic security system. In addition to the security factors, high level of adverse effects of conventional demilitarization practices emits on the environment. Classical demilitarization procedures greatly limit the disassembly of ordnance due to outdated technology, so a large number of items are removed by the destruction process. The methods of destroying ordnance from the aspect of eco-system protection are completely unacceptable. The development and deployment of new technologies that are widespread in other fields today is an opportunity to solve key problems. In the field of unconventional processing procedures, water jet based technologies, which represent non-thermal methods, do not lead to thermal changes of the material during the process. An important factor in these technologies is that they are, as such, fully developed and known, with all the influencing factors that can be varied. For the application of this technology for the purposes of deliberation, existing systems need to be modified and aligned with the requirements of the deliberation process. Analyzing and reviewing existing research in the world, there is a trend towards the adoption of new and environmentally friendly technologies. With the development of new technologies, the assortment of ordnance has been expanded, reducing the need for destruction of these assets significantly. The main goal of this paper is to look at all influential factors that are critical in the process of disassembly using classical methods. Based on the identified critical factors in the area of classic deliberation processes, it is necessary to consider the possibility of applying new technologies in order to modernize the deliberation process and, above all, to make it safe and environmentally friendly.

The paper presents the results of measuring the gearbox housing with the ATOS optical measuring system, the TRITOP system and the "TESA micro-hit 4-5-4" coordinate measuring machine. The aim of the study was to determine the differences in modern measuring systems and whether these differences affect the final measurement result when controlling parts of a complex configuration. At the beginning of the paper, the way of functioning of the used measuring systems and the results of research in this area are described. GOM Inspect software used for the ATOS and TRITOP measuring systems, while PC DMIS software used for the coordinate measuring machine. The analysis of the obtained results showed that there are significant differences in the measurement results and that the measuring systems used can't be applied with the same success to the measurement of parts of complex configuration such as the gearbox housing.

The application of new technologies in result of improving the pyrotechnic safety system, represents one of the priorities in the field of demilitarization of the EO. The conventional demilitarization procedures are partially or does not meet the prescribed standards at all in the field of pyrotechnic safety systems. The use of water-based techniques for the purpose of projectile delaboration directly influences the improvement of the pyrotechnic safety system, as well as the reduction of emissions of harmful and toxic chemical compounds into the working environment. The paper analyzes and research the possibility of improving the pyrotechnic safety system using abrasive waterjet and washout waterjet technology. Current research and conducted experiments show a wide area for the implementation of technology for the needs of projectile delaboration.

In the study of ways to reduce the friction losses of internal combustion (IC) engines, investigations of losses from elements in the piston assembly, the bearing system, and the valve train system are paramount. Mechanical and thermodynamic losses, wear and the emissions caused by lubricating oil combustion are principally influenced by the tribological behaviour of the piston assembly. The tribological performance of piston rings in reciprocating IC engines can only be fully understood when both lubrication and wear are considered in combination. This paper deals with physical-chemical tests that are part of the oil analysis and are used to access the condition of the system. Furthermore, the results of experimental research on the physical-chemical properties of the oil sampled from engines of the vehicles are shown.

The achievement of the required roughness of the surface (today known as surface texture) is of great importance in obtaining the required characteristics of the parts from the aspect of reduction of friction and wear. The most common methods for obtaining the required roughness, or surface textrure, are laser treatment and micro-processing by milling. 3D printingis increasingly being used to produce parts of wide range of applications. In order to obtain the neccessary surface texture, the use of 3D printing technology compared to traditional technologies is faster, more flexible and cheaper. So far, a small number of studies have been related to the surface characteristics of parts produced by 3D printing.Therefore, all the researches in this field in order to improve the friction and wear characteristics have significant role.This work provides an insight into the research of tribological characteristics of surface of samples made from polymers which are most commonly used materials in 3D printing technologies. The surface roughness, friction and wear are measured using tribometer and experimental method „Block-on-Disk“. The results shows significant differences in measured values in the tested materials, which demand further researches in order to.

Purpose The main purpose of the study was to analyze the relationship between cutting forces and tool wear during turning of steel 30CrNiMo8. Design/methodology/approach It is very important to find the optimal machining conditions to increase the tool life and to improve product quality. Width of tool wear was measured by universal microscope. Findings During experimental procedure, one chip shape was obtained for the given machining parameters. Results showed negligible tool wear for the given experimental conditions. In other words, the tool wear is negligible for one chip shape. Originality/value To increase tool wear, there are different chip shapes.

In this study, cutting tools average temperature was investigated by using thermal imaging camera of FLIR E50-type. The cubic boron nitride inserts with zero and negative rake angles were taken as cutting tools and round bar of EN 90MnCrV8 hardened steel was used as the workpiece. Since the life of the cutting tool material strongly depends upon cutting temperature, it is important to predict heat generation in the tool with intelligent techniques. This paper proposes a method for the identification of cutting parameters using neural network. The model for determining the cutting temperature of hard steel, was trained and tested by using the experimental data. The test results showed that the proposed neural network model can be used successfully for machinability data selection. The effect on the cutting temperature of machining parameters and their interactions in machining were analyzed in detail and presented in this study.

Temperature of cutting is a very important indicator of the cutting process. High specific pressures and high temperatures in the narrow cutting zone result in a drop of hardness of the tool material, the intensification of the abrasion and deformation of the cutting elements, losing the cutting abilities, and finally the failure of the cutting tool. The aim of this paper is to calculate the temperature fields using the existing numerical models for the simulation of thermodynamic processes on the wedge of the cutting tool (based on the finite element method). A special accent is given to the numerical calculation of temperatures in the conditions of continuous and discontinuous turning for specific cutting conditions (processing regime, tool geometry and thermo-mechanical characteristics of the tool materials and workpiece materials) using different simulation models. The Third Wave AdvantEdge software package was used for the simulation of orthogonal turning, and some of the results of the calculations of the temperature fields were compared with the results of experimental measurements.

U okviru ovog rada prikazani su rezultati ispitivanja utjecaja promjenljivih parametara obrade: koraka i broja okretaja na površinsku hrapavost legure aluminija 6005A-T6, pri CNC istosmjernoj i suprotnosmjernoj obradi glodanjem s alatima različitih dimenzija i od različitih materijala (Ø6 HSS, Ø6 VHM i Ø10 VHM). Navedene su karakteristike i klasifikacija aluminijuskih legura. Dana je definicija hrapavosti površine kod završnog glodanja (end milling) i navedeni parametri koji na nju utječu. Zaključeno je da je korak najutjecajniji parametar na hrapavost, dok je najmanja hrapavost postignuta glodanjem (up milling). Jednadžbe korelacije dale su dobro predviđanje površinske hrapavosti u slučaju obrade VHM glodalom Ø10. Rezultati eksperimenta poslužit će kao ulaz u model za upravljanje ulaznim parametrima procesa obrade putem regeneriranja NC koda u cilju poboljšanja kvalitete obrađene površine., The paper presents the research results of the impact of variable machining parameters: feed and spindle speed on surface roughness of Aluminium alloy 6005-T6, at CNC in the up and down milling with tools of different dimensions and different materials (Ø6 HSS, Ø6 VHM and Ø10 VHM). The properties and classification of Aluminium alloys are cited. The definition of surface roughness at end milling is given and parameters that affect it are specified. It was concluded that the feed is the parameter that has the most influence on surface roughens, while the lowest roughness is achieved by up milling. Correlation equations have provided good prediction of surface roughness in the case of machining of VHM by cutter Ø10. The results of the experiment will serve as an input into the model for control of input parameters of the machining process by regeneration of NC code for the purpose of quality improvement of machined surface.

Heat affected zone (HAZ) of the laser cutting process may be developed based on combination of different factors. In this investigation the HAZ forecasting, based on the different laser cutting parameters, was analyzed. The main goal was to predict the HAZ according to three inputs. The purpose of this research was to develop and apply the Extreme Learning Machine (ELM) to predict the HAZ. The ELM results were compared with genetic programming (GP) and artificial neural network (ANN). The reliability of the computational models were accessed based on simulation results and by using several statistical indicators. Based upon simulation results, it was demonstrated that ELM can be utilized effectively in applications of HAZ forecasting.

Adaptive grippers should be able to detect and recognize grasping objects. To be able to do it control algorithm need to be established to control gripper tasks. Compliant underactuated mechanisms with passive behavior can be used for modelling of adaptive robotic fingers. Undearactuation is a feature which allows fully adaptability of robotic fingers for different objects. In this study gripper with two fingers was established. Finite element method (FEM) procedure was used to optimize the gripper structural topology. Kinetostatic model of the underactuated finger mechanism was analyzed. This design of the gripper has embedded sensors as part of its structure. The use of embedded sensors in a robot gripper gives the control system the ability to control input displacement of the gripper and to recognize specific shapes of the grasping objects. Since the conventional control strategy is a very challenging task, soft computing based controllers are considered as potential candidates for such an application. The sensors could be used for grasping shape detection. Given that the contact forces of the finger depend on contact position of the finger and object, it is suitable to make a prediction model for the contact forces in function of contact positions of the finger and grasping objects. The prediction of the contact forces was established by using a soft computing (computational intelligence) approach. To perform the contact forces estimation adaptive neuro-fuzzy (ANFIS) methodology was used. FEM simulations were performed in order to acquire experimental data for ANFIS training. The main goal was to apply ANFIS network in order to find correlation between sensors’ stresses and finger contact forces. Afterwards ANFIS results were compared with benchmark models (extreme learning machine (ELM), extreme learning machine with discrete wavelet algorithm (ELM-WAVELET), support vector machines (SVM), support vector machines with discrete wavelet algorithm (SVM-WAVELET), genetic programming (GP) and artificial neural network (ANN)). The reliability of these computational models was analyzed based on simulation results.

Plasma jet cutting process is a well-known nonconventional thermo-electrical manufacturing process that is widely used in metal and shipbuilding industry. It uses the energy of highly ionized gas to cut various types of metal materials. Cutting process is determined by technological parameters whose values define the final cut quality results. Cut quality can be defined considering different characteristics such as: kerf width, bevel angle, surface roughness, dross height and heat affected zone. In this paper, a research on the influence of variable process parameters on the heat affected zone (HAZ) was conducted. An investigated material was aluminium alloy EN AW 5083. HAZ analysis was done by measuring hardness changes on the specimen cross sections and by microscopic observation of the material structure.

In the paper examined was the influence of the cutting regime parameters on surface roughness parameters during turning of hard steel with cubic boron nitrite cutting insert. In this study for modeling of surface finish parameters was used central compositional design of experiment and artificial neural network. The values of surface roughness parameters Ra and Rt were predicted by this two-modeling methodology and determined models were then compared. The results showed that the proposed systems can significantly increase the accuracy of the product profile when compared to the conventional approaches. The results indicate that the design of experiments with central composition plan modeling technique and artificial neural network can be effectively used for the prediction of the surface roughness for hard steel and determined significand cutting regime parameters.

Dross free laser cutting is very important in the application of laser cutting technology. This paper focuses on the development of a fuzzy logic model to predict dross formation in CO2 laser oxygen cutting of mild steel. Laser cutting experiment, conducted according to Taguchi’s experimental design using L25 orthogonal array, provided a set of data for the development of a fuzzy rule base. The predicting fuzzy logic model is based on using Mamdani-type inference system. Developed fuzzy logic model considered the cutting speed, laser power and assist gas pressure as inputs. Using this model the effects of the selected laser cutting parameters on the dross formation were investigated. Additionally, 3-D surface plots were generated to study the interaction effects of the laser cutting parameters. The analysis revealed that the cutting speed has the most significant effect, followed by laser power and assist gas pressure. The results indicated that the fuzzy logic modeling approach can be effectively used for the dross formation prediction in CO2 laser cutting of mild steel.

Machining of aluminum and its alloys requires the use of cutting tools with special geometry and material. Since there exists a number of cutting tools for aluminum machining, each with unique characteristics, selection of the most appropriate cutting tool for a given application is very complex task which can be viewed as a multi-criteria decision making (MCDM) problem. This paper is focused on multi-criteria analysis of VCGT cutting inserts for aluminum alloys turning by applying recently developed MCDM method, i.e. weighted aggregated sum product assessment (WASPAS) method. The MCDM model was defined using the available catalogue data from cutting tool manufacturers.

Solar energy is very important alternative energy due to the vase deposit. The main goal of the study was to analyze the solar radiation based on the four parameters: mean sea level (MSL), dry-bulb temperature (DBT), wet-bulb temperature (WBT) and relative humidity (RH). Adaptive neuro-fuzzy inference system (ANFIS) was used in order to estimate the parameters influence on the solar radiation prediction. Variable selection process was used to select the most dominant factors which affect the solar radiation prediction. The results shown that the DBT and RH are the most dominant factors for the solar radiation prediction.

The main aim of the study was to analyze the influence of six machining parameters on the chip shape formation and surface roughness as well during turning of Steel 30CrNiMo8. Three components of cutting forces were used as inputs together with cutting speed, feed rate, and depth of cut. It is crucial for the engineers to use optimal machining parameters to get the best results or to high control of the machining process. Therefore, there is need to find the machining parameters for the optimal procedure of the machining process. Adaptive neuro-fuzzy inference system (ANFIS) was used to estimate the inputs influence on the chip shape formation and surface roughness. According to the results, the cutting force in direction of the depth of cut has the highest influence on the chip form. The testing error for the cutting force in direction of the depth of cut has testing error 0.2562. This cutting force determines the depth of cut. According to the results, the depth of cut has the highest influence on the surface roughness. Also the depth of cut has the highest influence on the surface roughness. The testing error for the cutting force in direction of the depth of cut has testing error 5.2753. Generally the depth of cut and the cutting force which provides the depth of cut are the most dominant factors for chip forms and surface roughness. Any small changes in depth of cut or in cutting force which provide the depth of cut could drastically affect the chip form or surface roughness of the working material.

In this paper was presented 3D scanning application of dimensional inspection of parts obtained by cutting process. The dimensional and geometric deviations of cylindrical shoots of aluminum alloy parts, machined by applying different milling parameters, were measured using the coordinate measuring machine (CMM), PC DMIS software, three different optical scanners and GOM Inspect software. Results obtained using CMM were selected for reference and their comparison with the results obtained with scanners was conducted. It was noted that the differences between measured deviations exist and that further research should be focused on more precise defining and monitoring of conditions in measurement environment as well as the selection of the method of approximation and surface processing in order to increase the accuracy of the inspection with the 3D scanning device. A brief overview of the inspection procedure, inspection devices, scanning and surface reconstruction was also provided as well as the existing software applications for inspection.

During the past few decades, special attention has been devoted to developing modern instruments and methods of monitoring the tribomechanical characteristics of technical systems. Today, various physical, chemical and tribological methods are used in tribomechanical systems diagnosis. Scientific experience in technical system exploitation and maintenance has shown that the most effective way to predict failure is based on parameters that are reliable indicators of wear. Analysis of oil samples, which contain particles due to the wear process, enables an evaluation of the tribology condition of the system in the early phases of its use. This paper deals with tribological tests that are part of the oil analysis and are used to access the condition of the system. Furthermore, the results of experimental research on the tribological characteristics of the oil sampled from engines and gear transmissions of the vehicles (Mercedes O 345, PUCH 300GD and PINZGAUER 710M) are shown. All of these road vehicle were in regular use by the Serbian armed forces. The performed research has revealed some significant changes in the tribological characteristics of oil for engine and gear transmission lubrication.. These changes directly depend on the condition of the entire engine and transmission elements, i.e. depend on their functional characteristics. The presented method of oil analysis should contribute to an early detection of failures due to friction and wear processes in vehicle engines and reduce the need for preventive maintenance.

Na uzorcima korozijski postojanih čelika provedena su laboratorijska ispitivanja te ispitivanja u stvarnim uvjetima trošenja. Elektrokemijska ispitivanja provedena su radi provjere korozijske otpornosti modifi ciranih površina čelika. Na uzorcima korozijski postojanih čelika X20Cr13 i X17CrNi16-2 provedena je metalografska analiza i ispitivanje tvrdoće. Mogućnost primjene modifi ciranih površina na odabranim čelicima provjerena je ispitivanjem uzoraka svornjaka u stvarnim uvjetima trošenja. Uzorci svornjaka zavareni su REL postupkom, a korištena je elektroda Cr-Ni-Mn (18/8/6/). Dobiveni rezultati pokazuju da su indukcijski zakaljeni i naknadno nitrirani martenzitni čelici prosječno postigli otpornost trošenju do tri reda veličine veću u odnosu na dostavno stanje., On test samples of stainless steels, there were conducted laboratory tests and also sample tests in real wear conditions. Electrochemical testings were made towards control of corrosion resistance of modifi ed steel surfaces. On test samples of stainless steels X20Cr13 i X17CrNi16-2, there were conducted metallographic analysis and hardness testing. The possibility of applying modifi ed surfaces of selected steels was cntroled by sample testings in real wear conditions. Test bolts are welded with MMA procedure and it was used electrode Cr-Ni- Mn (18/8/6). Obtained results showed that induction hardened and post-nitrided martensitic stainless steels achieveed for three orders of magnitude bigger wear resistance in relation to asreceived condition., An den Proben der nichtrostenden Stähle wurden laboratorische Prüfungen durchgeführt in den realen Verschleiß Gegebenheiten. Elektrochemische Prüfungen wurden durchgeführt mit dem Ziel der Kontrolle der Korrosionsbeständigkeit bei Stählen mit modifi zierter Oberfl ächenstruktur. An Proben der nichtrostenden Stähle X20Cr13 und X17CrNi16-2, wurden metalographische Analysen und Härtemessungen durchgeführt. Eine Möglichkeit der Anwendung dieser Oberfl ächenmodifi zierten Stähle wurde an Bolzen in realen Verschleiß Gegebenheiten geprüft. Diese Bolzen wurden mit E-Hand und der Cr-Ni-Mn (18/8/6) Elektrode geschweißt. Die Resultate haben darauf eingewiesen dass die induktionsgehärteten und nachträglich nitrierende martensitischen Stähle im durchschnitt eine dreifach bessere Verschleißfestigkeit im Gegensatz zu den Stählen im gelieferten Zustand hatten.

U ovom je radu predstavljena metodologija višekriterijske optimizacije karakteristika kvalitete reza kod CO2 laserskog rezanja AISI 304 nehrđajućeg čelika (korozijski postojanog čelika). Za predviđanje karakteristika kvalitete reza kao što su hrapavost površine reza, širina reza i zona utjecaja topline, kreirani su matematički modeli pomoću umjetnih neuronskih mreža. Eksperiment laserskog rezanja je planiran i izveden prema Taguchijevom L27 ortogonalnom nizu, a eksperimentalni podaci su korišteni za treniranje umjetnih neuronskih mreža pomoću Levenberg-Marquardtovog algoritma. Matematički modeli umjetnih neuronskih mreža su kreirani uzimajući u obzir snagu lasera, brzinu rezanja, tlak pomoćnog plina i položaj fokusa kao ulazne parametre. Problem višekriterijske optimizacije je formuliran koristeći metodu težinskih koeficijenata, pri čemu su težinski koeficijenti, na osnovu kojih je izvršena kombinacija karakteristika kvaliteta reza u jednu ciljnu funkciju, određeni metodom analitičkog hijerarhijskog procesa., In this paper, multi-objective optimization of the cut quality characteristics in CO2 laser cutting of AISI 304 stainless steel was discussed. Three mathematical models for the prediction of cut quality characteristics such as surface roughness, kerf width and heat affected zone were developed using the artificial neural networks (ANNs). The laser cutting experiment was planned and conducted according to the Taguchi’s L27 orthogonal array and the experimental data were used to train single hidden layer ANNs using the Levenberg-Marquardt algorithm. The ANN mathematical models were developed considering laser power, cutting speed, assist gas pressure, and focus position as the input parameters. Multi-objective optimization problem was formulated using the weighting sum method in which the weighting factors that are used to combine cut quality characteristics into the single objective function were determined using the analytic hierarchy process method.

Glavne karakteristike površine obrađene abrazivnim mlazom vode su razlike u hrapavosti površine na vrhu i na dnu reza i pojava zakrivljenih linija-brazgotina koje su karakteristične za sve procese obrade s koncentriranim tokom velike energije. Zakrivljenost ovih linija je posljedica zaostajanja mlaza. Zaostajanje mlaza je uzrok grešaka pri rezanju radijusa i oštrih kutova. Parametri obrade imaju značajan utjecaj na ovu pojavu. Iz tog razloga nužno je poznavati i definirati utjecaj parametara obrade na ovu pojavu. Cilj ovog rada je istražiti utjecaj parametara obrade na zaostajanje mlaza, odnosno geometriju reza. Uzorci od AISI 304 obrađeni su abrazivnim mlazom vode različitim posmičnim brzinama, radnim tlakovima i protocima abraziva. Zaostajanje mlaza mjereno je na 10 mjernih mjesta preko dubine reza. Na temelju tih rezultata, formiran je odnos između zaostajanja mlaza i parametara obrade., The main characteristics of the surface machined with the abrasive water jet are the differences in surface roughness at the top and bottom of the cut and the appearance of curved lines-striations, which are characteristic for all machining processes with the concentrated stream of high energy. The curvature of these lines is the consequence of jet lagging. Jet lagging is the cause of errors in cutting of radius and sharp corners. The machining parameters have a great influence on this phenomenon. Therefore, it is necessary to know and to define the influence of machining parameters on this phenomenon. The aim of this paper is to investigate the effect of machining parameters on the jet lagging, i.e. cut front geometry. The specimens of AISI 304 were machined by the abrasive water jet under varying traverse speeds, operating pressures and abrasive mass flow rates. The jet lagging was measured at ten monitoring points by the depth of cut. Based on these results, the relationship between the jet lagging and machining parameters has been formed.