Explosive forming is one of the non-conventional impulse technologies of metal forming technologies and it is a relatively young technology that has not been fully explored. The origin, development and application of explosive forming technology is given in this paper, and the advantages and disadvantages are also described. Given the specificity of this technology, this paper presents the calculation of the mass of the explosive as the most important factor in this process and the calculation of the pressure of the shock wave. In fact, with conventional deep drawing technologies, it is possible to design the technology and follow the same steps to reach products of different dimensions. In explosive forming, this is a problem, and it is not possible to follow these rules. Experiments of explosive forming can only be performed by employees trained to work with explosives, following prescribed procedures.

Currently, the world is facing major changes. Research and development of innovations in new technologies, the rapid pace of implementation of these innovations and especially digitization and automation, play a major role in shaping the future world. Technological innovations promise the transformation of the world we live in all its dimensions. However, in order for the benefits of innovation to be adequately exploited, it is necessary for us as a society to adapt to the coming changes. We must also keep in mind that these changes come at a time previously marked by uncertainty, turbulent changes and hyper competitiveness. The development and implementation of new technologies in business is motivated by a number of technical and economic reasons: improving the quality of finished products (machining, etc.), increasing productivity and reducing the share of work (assembly process), increasing the degree of homogeneity of product quality in all production processes related to the application of robotic technology, increasing the level of safety, reducing labor engagement in routine and reproducible processes, minimizing total production costs and maintenance costs of the device in the production process, all with the purpose of adequate responses to competition challenges and increasingly stringent customer requirements. Although the concept of Industry 4.0 is already widely used in developed countries, it is a relatively new concept in the Western Balkans, including Bosnia and Herzegovina. Most company managers understand the benefits of "smart" production and are familiar with new trends in the industry, intend to gradually introduce smart solutions, methods and technologies, and only a small number of companies in Bosnia and Herzegovina currently implement the concept of Industry 4.0. The paper presents the results of research on the application of Industry 4.0 technologies in all branches of the economy in Bosnia and Herzegovina and especially the representation of Industry 4.0 in small, medium and large enterprises. Detection of awareness of certain groups about the concepts of Industry 4.0 was performed, and the research method itself is based on an online survey.

Explosive forming appeared at the end of the 19th century as unconventional technology that provides new methods to get workpieces with bigger dimensions and complex geometries. As a source of energy this technology uses explosives. Explosive, as such, is relatively inexpensive and theoretically with it, it is possible to get any amount of energy that is needed. Explosive forming is used with other technologies such as deep drawing, expansion of pipes, welding etc. One of the main explosive characteristics is the velocity of detonation that can be determined, inter alia, with the Dautrich method. This paper clarifies the method and gives a case study with explosive Vitezit 20.

This paper presents theoretical approach and complex experimental research which was conducted within the real production conditions of cold roll forming channel sections. The experimental investigation was focused on forming forces measuring on the rolls and the deflections of roll stands due to the forming loads. The comparison and analysis of the obtained experimental results was performed for the majority roll stands. Based on the experimental results mathematical modelling of the forming a force‐roll load was performed by response surface methodology for different values of the input parameters of the process: material properties, sheet thickness, and sheet width. The defined force model and experimental research show insufficient energetic and technological utilization of the existing production line. After the conducted research in the production process a sheet thickness of up to 1.40 mm is used instead of 0.70 mm, and the utilization of the installed energy has increased from 20 % to 75 %. This is confirmed by the measured deformations of the roll stands and the energy consumption of the powered electric motor. Through realized modernization of the cold roll forming production line, 30 % higher productivity is achieved, which is a result of optimal number planning of roll forming stations and approximately the same load of all roll stands, as well as the higher flow rate of the profile sheet.

Optimizacija parametara obrade tokarenja s vise kriterija kvalitete uporabom Grey relacijske analize Izvorni znanstveni clanak Optimizacija procesa obrade je neophodna za postizanje vece produktivnosti i visoke kvalitete proizvoda kako bi ostali tržisno konkurentni. Ovaj rad istražuje vise-kriterijsku optimizaciju procesa tokarenja s optimalnom kombinacijom parametara obrade koji osiguravaju minimalnu hrapavost povrsine (Ra) s maksimalnim ucinkom uklanjanja materijala (MRR) uporabom Grey-based Taguchi metode. Razmatrani parametri obrade tokarenjem su brzina rezanja, posmak i dubina rezanja. Primjenom Taguchijevog L9 (3 4 ) ortogonalnog plana provedeno je devet eksperimenata te je koristena Grey relacijska analiza kako bi se rijesio visekriterijski problem optimizacije. Temeljem vrijednosti Grey relacijskog stupnja utvrđene su optimalne razine parametara. Signifikantnost parametara na sveukupne kriterije kvalitete procesa tokarenja ocijenjena je analizom varijance (ANOVA). Optimalne vrijednosti parametara dobivene tijekom istraživanja potvrđene su verifikacijskim eksperimentom. Kljucne rijeci: ANOVA; Grey relacijska analiza; Taguchijeva metoda; tokarenje; visekriterijska optimizacija

The fundamental basis for implementation of reengineering is: experimental measurement of forces and torques on the rollers-tools production line for profile sheet metal forming. The paper presents the experiments of measuring forces and torques, modeling and simulation in the aim of redesigning the process of sheet metal forming, selecting of the optimal process of sheet metal forming for each forming module and totally for the production line and increasing productivity on production lines. In the experimental research forces and torques were measured on the rollers of forming modules for profile forming of sheets for different values of the input parameters of the process: material type σm, sheet thickness s and sheet width b. Based on the experimental results mathematical models were defined, which enabled the analysis and implementation of reengineering the production system.

Original scientific paper The fundamental basis for implementation of reengineering is: experimental measurement of forces and torques on the rollers-tools production line for profile sheet metal forming. The paper presents the experiments of measuring forces and torques, modeling and simulation in the aim of redesigning the process of sheet metal forming, selecting of the optimal process of sheet metal forming for each forming module and totally for the production line and increasing productivity on production lines. In the experimental research forces and torques were measured on the rollers of forming modules for profile forming of sheets for different values of the input parameters of the process: material type σm, sheet thickness s and sheet width b. Based on the experimental results mathematical models were defined, which enabled the analysis and implementation of reengineering the production system.

”REINŽENJERING PROIZVODNIH PODUZECA – Razvoj i modernizacija proizvodnje” je djelo gdje je na jednom mjestu prikazan razvoj moderne proizvodnje od osnova proizvodnje, nove proizvodne filozofije, razvoja proizvoda, modernih proizvodnih i inteligentnih sistema do metodologije unapređenja proizvodnje primjenom reinženjeringa i mjerenja rezultata reinženjeringa. Prema misljenju istaknutih i kompetentnih recenzenata knjiga bi trebala imati veliki znacaj u razvoju moderne proizvodnje i edukaciji, a neophodna je svakom inženjeru, tehnologu, konstruktioru, menadžeru, edukatoru itd., jer konkretno govori o razvoju, modernizaciji i sticanju konkurentske prednosti na globalnom tržistu, sto pokazuje i nekoliko glavnih naslova ove knjige: 1. Uvod: zadatak i cilj reinženjereinga Stanje domace proizvodnje i konkurentnost 2. Osnove reinženjeringa proizvodnje. 3. Osnove proizvodnje: modeli moderne proizvodnje s prikazom svih modela 4. Proizvodni i poslovni sustavi/sistemi 5. Nova proizvodna filozofija i konkurentska sposobnost 6. Suvremeno tržiste, globalizacija, moderna proizvodnja i konkurentnost 7. Temelji razvoja moderne proizvodnje sposobne za globalno tržiste 8. Primjena reinženjeringa i alati za provedbu: inovacije, implementacija znanja... moderne i napredne proizvodne tehnologije, izbor i primjena, kompjutorski integrirana proizvodnja, koncept, primjena i prednosti, planiranje i upravljanje modernom proizvodnjom... 9. Reinženjering u razvijenim zemljama (EU i SAD) i zemljama tranzicije 10. Metodologija izvođenja reinženjeringa: faze izvedbe, algoritam toka reinženjeringa... 11. Tko i kako izvodi reinženjering:... 12. Mjerenje rezultata izvedenog reinženjeringa. 13. Projekt reinženjeringa: planiranje, upravljanje i evaluacija projekta 14. Strateske odluke za implementaciju reinženjeringa 15. Reinženjering proizvodnje: izazov sadasnjosti i buducnosti...

In the thin-sheet metal shaping processes it is possible to use explosion energy for volume shaping as well as for other processes of thin-sheet metal shaping, like surface hardening, riveting calibration, sintering, casting under pressure, cast cleaning, mounting, etc. In the observed case there will be presented a process of determining dynamicity coefficient both based on existing theoretic equations for determination of required pressure, and based on experimental results of testing. As a matter of fact, a dynamicity coefficient is ratio between dynamic and static pressures and will be deduced from conditions of the equal deformation degree on the occasion of explosive-induced deep drawing of sphere-bottomed plate. In the observed case by means of explosion there was deeply drawn a sphere-bottomed plate with diameter 200 mm made of steel 4580. Explosive’ s detonation velocity was 2994 m/s and 6105 m/s. The explosive used was “ Vitezit 20” , while medium for energy transmission was water.

Purpose of this research is determination of the optimal cold forward extrusion parameters with objective the minimization of tool load. This paper deals with the different optimization approaches relating to determine optimal values of logarithmic strain, die angle and coefficient of friction with the purpose to find minimal tool loading obtained by cold forward extrusion process. To achieve this, it has been carried out two experimental plans based on factorial design of experiment and orthogonal array. By using these plans it was performed classical optimization, according to response model of extrusion forming force, and the Taguchi approach, respectively. Experimental verification of optimal forming parameters with their influences on the forming forces was done. The experimental results showed an improvement in minimization of tool loading. It was compared results of optimal forming parameters obtained with different optimization approaches and based on that the analysis of the characteristics (features and limitations) of both techniques.

Purpose: This research is determination of the optimal cold forward extrusion parameters with objective the minimization of tool load. Design/methodology/approach: This paper deals with the different optimization approaches relating to determine optimal values of logarithmic strain, die angle and coefficient of friction with the purpose to find minimal tool loading obtained by cold forward extrusion process. To achieve this, it has been carried out two experimental plans based on factorial design of experiment and orthogonal array. By using these plans it was performed classical optimization, according to response model of extrusion forming force, and the Taguchi approach, respectively. Findings: Experimental verification of optimal forming parameters with their influences on the forming forces was done. The experimental results showed an improvement in minimization of tool loading. It was compared results of optimal forming parameters obtained with different optimization approaches and based on that the analysis of the characteristics (features and limitations) of both techniques. Research limitations/implications: Suggestion for future research it will be application of evolutionary algorithms namely model prediction of the process by genetic programming and optimization of extrusion parameters by genetic algorithm. Practical implications: a practical (industrial) implication on the smallest energy consumption, longer tool life, better formability of the work material and the quality of the finished product. Originality/value: This paper is obtained original extrusion force model for experimental domain of forming parameters and identification of parameters influence in that model.

Purpose: of this paper is test of the tribological state in metal forming processes with main aims the determination of state on the tool contact surface (contact stresses and friction coefficient) friction coefficient modelling and simulation and to present the original method of defining contact stresses tf and pn and coefficient of contact friction mi. Design/methodology/approach: of this research is review of contact stresses determination methods, general principles of stochastic modelling, experimental friction test and modelling, examples tribological state test and simulaton by deep drawing and drawing processes. Main achievement are: original experimental identification of contact stresses, original experimental of tools for measurement of contact stresses, mathematical model for defining the tribological state. Application methods of this research are: experimental, tribological state test in forming processes by means of experiment and modelling, statistical and direct contact stresses determining method. Findings: experimental and stochastic modelling of tribological parameters of the forming processes and verification of mathematical model. The tribological state test is performed on the basis of experimental investigations and stochastic modelling. Research limitations/implications: modelling and optimization of tool geometry and selection of optimal lubricators, development experimental methods in the determination of contact stresses, etc. Practical implications: Results of investigations in processing conditions show that the desired effects can be achieved: increased durability of tools 20-40%, reduced stagnation time in the machining process 20-30%, increase on the productivity of the forming process 15-30% and less energy consumption up to 15%. Originality/value: of this paper is obtained original mathematical model for defining coefficient contact friction and contact temperature on the contact surface of tool. Also, is obtained original experimental tool for measurement of contact stresses.