Joze Duhovnik - Profile on Academia.edu (original) (raw)
Papers by Joze Duhovnik
Journal of Industrial Information Integration
Information systems are key enablers for the integration and reliable management of the product d... more Information systems are key enablers for the integration and reliable management of the product development process. Information systems are the backbone that connects various sub-processes and enables flexible product customization. Fast, robust, and cost-efficient product adaptation is especially important in one-of-a-kind production. This paper presents a transformation of the product development design process for large power transformers into a competitive and smartly supported process. One-of-a-kind production is specific, as each product must be customized, wherefore a robust design process well supported by IT plays a key role in creating a digital twin and the product's final value. Based on a systematic analysis of the sample company, this paper proposes a model for the complete renewal of information systems and of working methodology, where reorganization is demonstrated in an increase of overall effectiveness.
This paper aims at showing the possibility of improving the initial phase of design process using... more This paper aims at showing the possibility of improving the initial phase of design process using the matrix function multi-structured form of products and their requests. The developed matrix model is a tool which by using a mathematical model interconnects functions and technical systems that solve them. This is one of the main differences with regard to morphological matrix. By mutual linking of matrices the matrix structure is generated in which the whole functional structure of a product is stored. For the sake of uniformity the functions are described by parameters defined from physical laws. In this way the complete knowledge about a product is registered in matrices enabling the generation of the variant and new products. The model is implemented into a prototype computer Web application with the central relational data base. A higher quality, faster and cheaper management of the design process is thus made possible.Cilj ovoga rada je prikazati mogućnost poboljšanja inicijal...
In a competitive knowledge-based environment the role of creativity in new product development (N... more In a competitive knowledge-based environment the role of creativity in new product development (NPD) has increased. The university as the provider of scientific and technological knowledge has become a key player in NPD, as a supplier of knowledge and human capital and as the physical space for new enterprises. The boundaries between science and technology, university and industry are in flux. This article therefore examines the environmental, strategic and organizational factors influencing innovation in NPD process on an example of an Academic Virtual Enterprise (AVE) that was applied in a design course called European Global Product Realization. AVE represents a creative working environment for students, where they act as real professionals in solving a real-life design problem.U konkurentnom okruženju utemeljenom na znanju povećana je uloga kreativnosti u razvoju novog proizvoda (RNP). Sveučilište kao pružatelj znanstvenog i tehnološkog znanja postalo je ključni igrač u RNP, kao...
Springer Tracts in Mechanical Engineering, 2018
Reverse engineering has been practised since the beginning of technology. Fundamentally, it is ab... more Reverse engineering has been practised since the beginning of technology. Fundamentally, it is about the identification of existing technical and natural solutions, and their reconstruction into new, identical or even improved technical solutions. Over the years it has flourished systematically, thanks to the development of new and technologically increasingly advanced and economically affordable measuring procedures, which allows the accurate reconstruction of not only technical principles but also detailed shapes and dimensions. This chapter explains the position of reverse engineering in the modern design and development process. It also introduces the main measuring methods for capturing data on the geometry of physical objects. These methods are divided into groups, depending on how they work and the physical laws on which they are based. We also present the main advantages and disadvantages of particular groups of methods, and recommendations for their application where the best results can be achieved.
The paper describes a method and a tool to support concept generation and its structural synthesi... more The paper describes a method and a tool to support concept generation and its structural synthesis. The method includes automated generation of conceptual technical systems and their semi-automated structural synthesis. In the structural synthesis phase, the emphasis of the research is on structural visualization of automatically generated conceptual TS. Physical laws are used for description of automatically generated technical systems while the relations between parts of structure that contribute to realization of the functions are defined by basic schemata.
The development of an innovative product that will be widely accepted on the market is not just a... more The development of an innovative product that will be widely accepted on the market is not just a question of creating innovative ideas and providing suitable functionality but also of good timing. In the last years we have seen a substantial increase in interest into e-mobility and many producers have already recognized and ventured into this niche with high rewards. E-bikes are also an emerging product in this field, which have gained a lot of interest in the last years, and are becoming widely demanded globally. Being involved in the R&D process of a similar product, namely a central drive e-bike, in collaboration with several industrial partners we have gained deep insight into the challenges of entering a by now fairly mature market with a new, high quality and competitive product. The development methodology was first based on a thorough benchmarking process and the elaboration of a functional structure that precisely describes the technical problem. This way we could identify...
Guidelines for a Decision Support Method Adapted to NPD Processes, 2007
The world is in the middle of the globalization process that, among other things, forces companie... more The world is in the middle of the globalization process that, among other things, forces companies into acquisitions and mergers, and strategic alliances. This leads to the merging of geographically, organizationally and culturally heterogeneous human resources, including product developers. Market and organizational changes, the integrated product development process, and available information and communication technologies (ICT), present a number of challenges for future product developers. An appropriate response to these challenges is to create a solid basis for strategies to combat stronger competition, since existing educational programmes have provided this only to a small extent. European-Global Product Realization (E-GPR) course is one of possible educational programmes; the paper presents some experiences based on running the course.
Springer Tracts in Mechanical Engineering, 2019
The use of general descriptive names, registered names, trademarks, service marks, etc. in this p... more The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
The product development teams become organizationally, geographically and culturally dispersed ov... more The product development teams become organizationally, geographically and culturally dispersed over the globe. The strategic alliance of several European universities has formed an "E-GPR" (European Global Product Realization) study course as a response to the product development challenges. The effective means for long-distance communication enabled intensive collaboration between competitive student teams. The industrial partners provided the project tasks to be solved within a short one semester time and required functional prototypes. We describe the setup of the course, the results, and provide some reflections. The course evolved during its repetitions over 7 consecutive years. The project work has been thoroughly monitored and the results have been assessed and quantified. The students should gain valuable experience in communication, organization, public presentation of work and prototyping and thus should better be prepared to tackle challenges associated with wor...
The development of information technologies enables one to regard a product's life cycle as a... more The development of information technologies enables one to regard a product's life cycle as a unified process from idea through development, manufacture and distribution to servicing. The transition to e-business within companies contains great potential for increasing their productivity and competitiveness. This paper analyses the idea that a company should first be capable of doing e-business internally, before it can start efficiently operating with external clients. The paper analyses product development and engineering change processes in detail. An example from Domel presents a solution for product documentation management using a SAP information system and PLM (Product Life cycle Management) module.
The shape of the tooth profile affects the stress-strain state in the gear. In the case of a fati... more The shape of the tooth profile affects the stress-strain state in the gear. In the case of a fatigue failure the stress state is a decisive criterion for the lifetime of the gear. The shape of the tooth flank affects the magnitude of the contact pressure in the contact of the meshing teeth. The consequence of which are surface cracks and pitting. The shape of the tooth root influences the magnitude of the root stress, which, when limit is exceeded, leads to root cracks and teeth breakage. Many different types of gearing are known, but in the practice most widely used is the involute one. Other types of gearing become interesting especially when polymer materials are being used. If the gears are injection molded the type of gearing does not affect the cost of the tool. In the case of metal gears, standardized tools for involute gearing make the use of other special types of gearing economically unjustified. Our research is focused on the S-gears, which got their name from the S-shape...
Guidelines for a Decision Support Method Adapted to NPD Processes, 2007
The paper presents a method of graphical embodiment of abstract conceptual solutions which were a... more The paper presents a method of graphical embodiment of abstract conceptual solutions which were automatically generated by chaining of physical laws. For this purpose, a repository of 125 physical laws was generated, where each law is also presented graphically as a basic schema composed out of maximum four graphical elements with the ability to be freely shaped. This tool enables application of physical laws for the analysis of existing technical systems and also for synthesis of new ones. Procedure of formalising the transition from physical laws to a schema of a future technical system is indicated. Physical laws are used to conceptualize or upgrade existing technical systems where the main focus is on their synthesis.
This paper presents model and application of product function matrix and its requests model. Mode... more This paper presents model and application of product function matrix and its requests model. Model is implemented in developed computer Web application. With connections and winning parameters relation between Blower matrix and Diffuser matrix is presented and achieved. In this way it is possible to generate complete product function structure stored in matrix structure. When complete matrix and function structure is created, it is possible to generate physical (shape) product structure.
Priporočila 7. razvojne skupine za procesno tehnologijo za povečanje konkurenčnosti Slovenije : strateški dokument 7. razvojne skupine za Procesno tehnologijo
Original scientific paper A developed model of the first structural shape of the matrix of produc... more Original scientific paper A developed model of the first structural shape of the matrix of product function and its requests model have been shown in practice. It relates functions of the product and its requests model, and technical systems that solve them. Functions are described by parameters, determined by physical laws. The technical systems and functions are related among themselves through correlations that fill the field of the matrix. The correlations are determined through winning parameters. Winning parameters are determined from the set of parameters of each function that have the greatest importance and influence on a specific function. The model is implemented into a developed prototype computer system. The first structural shape of the product function matrix and its requests model for the stator of the electrical motor of the intake unit have been generated through the prototype computer system. By implementing the product function matrix and its requests model in the process of product conceptual design, it becomes possible for a designer to examine himself by comparing the possibilities of implementation of new ideas with previously built products. Izvornoznanstveni članak U radu je prikazan razvijeni model prvog strukturnog oblika matrice funkcije proizvoda i model njezinih zahtjeva koji dovodi u međusobne odnose funkcije proizvoda i tehničke sustave koji ih rješavaju. Funkcije su opisane parametrima, određenim iz fizikalnih zakona. Tehnički sustavi i funkcije povezani su između sebe preko poveznica koje popunjavaju polja matrice. Poveznice su određene preko pobjednih parametara. Pobjedni parametri se određuju iz skupa parametara svake funkcije te imaju najveći značaj i utjecaj na određenu funkciju. Model je implementiran u razvijeni prototipni računalni sustav, pomoću kojeg je u ovom radu generiran prvi strukturni oblik matrice funkcije proizvoda i njezinih zahtjeva za stator elektromotora usisne jedinice. Primjenom modela matrice funkcije proizvoda i njihovih zahtjeva, u procesu koncipiranja proizvoda, omogućuje se konstruktoru preispitivanje samoga sebe uspoređujući mogućnosti realizacije novih ideja s već prethodno napravljenim proizvodima.
Once a product is developed and its manufacture begins, its level of excellence immediately start... more Once a product is developed and its manufacture begins, its level of excellence immediately starts decreasing due to other competitive products on the market. Its life on the market can be prolonged by continual product improvements. A longer product lifetime also increases its profitability, because the development of a new family of products is associated with considerable costs. The paper presents product re-engineering using an example of a vacuum cleaner motor and its positioning in the product development cycle. The development of vacuum cleaner motors (motor and turbine assembly) is progressing in the direction of increasing the number of revolutions and decreasing their mass and volume. The performed analysis of vacuum cleaner motor construction indicated several possibilities for increasing the number of revolutions. The basic problem concerns the influence of individual components on critical speed. The paper assesses the applicability of individual methods for the analysi...
The results of a numerical simulation of meshing polymer and composite gears are presented in the... more The results of a numerical simulation of meshing polymer and composite gears are presented in the paper. The numerical model used for simulations was built in Ansys Workbench 15.0, using the finite element method to obtain the solution. The results are related to the gear tests, performed by the authors and presented in the literature. A detailed stress and strain analysis of meshing gears is presented. On the basis of which gears of different polymer and composite materials can be rated and appropriate material combinations can be chosen. With the presented numerical model, root and flank stresses in each meshing point along the path of contact can be calculated. Stresses (root and flank) obtained by simulations will be compared with the stresses calculated according to VDI 2736 guideline. The numerical model takes into account friction between the tooth flanks in contact, which significantly contributes to improving the accuracy of the numerical solution. (Less)
Original scientific paper Vortex wake interaction of a rectangular prism is numerically investiga... more Original scientific paper Vortex wake interaction of a rectangular prism is numerically investigated. The wind barrier is accurately geometrically represented with a threedimensional model in the numerical simulation. The barrier model consists of horizontal bars with different inclination angles. The unsteady Reynoldsaveraged Navier-Stokes (URANS) computation is applied because the flow is not statistically stationary. The shear stress transport (SST) k-ω turbulence model is used because it shows good behavior in adverse and separated flows. Experimental study is performed to confirm the numerical data. The aim is to enhance the present level of understanding regarding bluff body wake interference flow and analyze the barrier’s bar inclination effect on the sheltered object. As the bar inclination angle decreases, the bleed flow gets stronger, which results in a smaller reduction of the drag imposed on the sheltered object. The turbulent structures between the barrier and the shelt...
Research in Engineering Design, 2021
The smart factories that are already beginning to appear employ a completely new approach to prod... more The smart factories that are already beginning to appear employ a completely new approach to product creation. Smart products are uniquely identifiable and know both their current status and alternative routes to achieving their target state. Smart factories allow individual customer requirements to be met, meaning that even one-off items can be manufactured profitably. In smart industry, dynamic business and engineering processes enable last-minute changes to design and production, delivering the ability to respond flexibly to disruptions and failures on behalf of suppliers. This paper presents a case study of product development and design process renovation according to changeability paradigm in one-of-a-kind industrial environment. It demonstrates how integration of changeability with agile design strategies crucially contribute to improve the operations of a highly individualized product development business. Successful management of ‘never-ending’ engineering changes appears t...
Mechanism and Machine Theory, 2020
The presented work is focused on the development of a comprehensive thermo-mechanical model for p... more The presented work is focused on the development of a comprehensive thermo-mechanical model for predicting the temperature rise in thermoplastic polymer spur gears with any desired profile geometry while running. The specific constitutional behavior of thermoplastics influences the gear-meshing pattern, which can deviate substantially from ideal gear meshing, as typically exhibited by metal gears in moderate-loading conditions. Taking this aspect into account is of paramount importance if realistic temperature-rise predictions are to be made. The thermal response of the considered gear pair is studied thoroughly from both the analytical and experimental standpoints. Good agreement was found between the results of the model and the experimental measurements performed using a high-speed thermal imaging infrared camera, although it was also observed that the reallife temperature rise can increase noticeably if large geometric tolerance deviations from the ideal profile geometry are present. The presented experimental approach also offers the possibility to observe the temperature rise inside and outside the meshing cycle.
Journal of Industrial Information Integration
Information systems are key enablers for the integration and reliable management of the product d... more Information systems are key enablers for the integration and reliable management of the product development process. Information systems are the backbone that connects various sub-processes and enables flexible product customization. Fast, robust, and cost-efficient product adaptation is especially important in one-of-a-kind production. This paper presents a transformation of the product development design process for large power transformers into a competitive and smartly supported process. One-of-a-kind production is specific, as each product must be customized, wherefore a robust design process well supported by IT plays a key role in creating a digital twin and the product's final value. Based on a systematic analysis of the sample company, this paper proposes a model for the complete renewal of information systems and of working methodology, where reorganization is demonstrated in an increase of overall effectiveness.
This paper aims at showing the possibility of improving the initial phase of design process using... more This paper aims at showing the possibility of improving the initial phase of design process using the matrix function multi-structured form of products and their requests. The developed matrix model is a tool which by using a mathematical model interconnects functions and technical systems that solve them. This is one of the main differences with regard to morphological matrix. By mutual linking of matrices the matrix structure is generated in which the whole functional structure of a product is stored. For the sake of uniformity the functions are described by parameters defined from physical laws. In this way the complete knowledge about a product is registered in matrices enabling the generation of the variant and new products. The model is implemented into a prototype computer Web application with the central relational data base. A higher quality, faster and cheaper management of the design process is thus made possible.Cilj ovoga rada je prikazati mogućnost poboljšanja inicijal...
In a competitive knowledge-based environment the role of creativity in new product development (N... more In a competitive knowledge-based environment the role of creativity in new product development (NPD) has increased. The university as the provider of scientific and technological knowledge has become a key player in NPD, as a supplier of knowledge and human capital and as the physical space for new enterprises. The boundaries between science and technology, university and industry are in flux. This article therefore examines the environmental, strategic and organizational factors influencing innovation in NPD process on an example of an Academic Virtual Enterprise (AVE) that was applied in a design course called European Global Product Realization. AVE represents a creative working environment for students, where they act as real professionals in solving a real-life design problem.U konkurentnom okruženju utemeljenom na znanju povećana je uloga kreativnosti u razvoju novog proizvoda (RNP). Sveučilište kao pružatelj znanstvenog i tehnološkog znanja postalo je ključni igrač u RNP, kao...
Springer Tracts in Mechanical Engineering, 2018
Reverse engineering has been practised since the beginning of technology. Fundamentally, it is ab... more Reverse engineering has been practised since the beginning of technology. Fundamentally, it is about the identification of existing technical and natural solutions, and their reconstruction into new, identical or even improved technical solutions. Over the years it has flourished systematically, thanks to the development of new and technologically increasingly advanced and economically affordable measuring procedures, which allows the accurate reconstruction of not only technical principles but also detailed shapes and dimensions. This chapter explains the position of reverse engineering in the modern design and development process. It also introduces the main measuring methods for capturing data on the geometry of physical objects. These methods are divided into groups, depending on how they work and the physical laws on which they are based. We also present the main advantages and disadvantages of particular groups of methods, and recommendations for their application where the best results can be achieved.
The paper describes a method and a tool to support concept generation and its structural synthesi... more The paper describes a method and a tool to support concept generation and its structural synthesis. The method includes automated generation of conceptual technical systems and their semi-automated structural synthesis. In the structural synthesis phase, the emphasis of the research is on structural visualization of automatically generated conceptual TS. Physical laws are used for description of automatically generated technical systems while the relations between parts of structure that contribute to realization of the functions are defined by basic schemata.
The development of an innovative product that will be widely accepted on the market is not just a... more The development of an innovative product that will be widely accepted on the market is not just a question of creating innovative ideas and providing suitable functionality but also of good timing. In the last years we have seen a substantial increase in interest into e-mobility and many producers have already recognized and ventured into this niche with high rewards. E-bikes are also an emerging product in this field, which have gained a lot of interest in the last years, and are becoming widely demanded globally. Being involved in the R&D process of a similar product, namely a central drive e-bike, in collaboration with several industrial partners we have gained deep insight into the challenges of entering a by now fairly mature market with a new, high quality and competitive product. The development methodology was first based on a thorough benchmarking process and the elaboration of a functional structure that precisely describes the technical problem. This way we could identify...
Guidelines for a Decision Support Method Adapted to NPD Processes, 2007
The world is in the middle of the globalization process that, among other things, forces companie... more The world is in the middle of the globalization process that, among other things, forces companies into acquisitions and mergers, and strategic alliances. This leads to the merging of geographically, organizationally and culturally heterogeneous human resources, including product developers. Market and organizational changes, the integrated product development process, and available information and communication technologies (ICT), present a number of challenges for future product developers. An appropriate response to these challenges is to create a solid basis for strategies to combat stronger competition, since existing educational programmes have provided this only to a small extent. European-Global Product Realization (E-GPR) course is one of possible educational programmes; the paper presents some experiences based on running the course.
Springer Tracts in Mechanical Engineering, 2019
The use of general descriptive names, registered names, trademarks, service marks, etc. in this p... more The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
The product development teams become organizationally, geographically and culturally dispersed ov... more The product development teams become organizationally, geographically and culturally dispersed over the globe. The strategic alliance of several European universities has formed an "E-GPR" (European Global Product Realization) study course as a response to the product development challenges. The effective means for long-distance communication enabled intensive collaboration between competitive student teams. The industrial partners provided the project tasks to be solved within a short one semester time and required functional prototypes. We describe the setup of the course, the results, and provide some reflections. The course evolved during its repetitions over 7 consecutive years. The project work has been thoroughly monitored and the results have been assessed and quantified. The students should gain valuable experience in communication, organization, public presentation of work and prototyping and thus should better be prepared to tackle challenges associated with wor...
The development of information technologies enables one to regard a product's life cycle as a... more The development of information technologies enables one to regard a product's life cycle as a unified process from idea through development, manufacture and distribution to servicing. The transition to e-business within companies contains great potential for increasing their productivity and competitiveness. This paper analyses the idea that a company should first be capable of doing e-business internally, before it can start efficiently operating with external clients. The paper analyses product development and engineering change processes in detail. An example from Domel presents a solution for product documentation management using a SAP information system and PLM (Product Life cycle Management) module.
The shape of the tooth profile affects the stress-strain state in the gear. In the case of a fati... more The shape of the tooth profile affects the stress-strain state in the gear. In the case of a fatigue failure the stress state is a decisive criterion for the lifetime of the gear. The shape of the tooth flank affects the magnitude of the contact pressure in the contact of the meshing teeth. The consequence of which are surface cracks and pitting. The shape of the tooth root influences the magnitude of the root stress, which, when limit is exceeded, leads to root cracks and teeth breakage. Many different types of gearing are known, but in the practice most widely used is the involute one. Other types of gearing become interesting especially when polymer materials are being used. If the gears are injection molded the type of gearing does not affect the cost of the tool. In the case of metal gears, standardized tools for involute gearing make the use of other special types of gearing economically unjustified. Our research is focused on the S-gears, which got their name from the S-shape...
Guidelines for a Decision Support Method Adapted to NPD Processes, 2007
The paper presents a method of graphical embodiment of abstract conceptual solutions which were a... more The paper presents a method of graphical embodiment of abstract conceptual solutions which were automatically generated by chaining of physical laws. For this purpose, a repository of 125 physical laws was generated, where each law is also presented graphically as a basic schema composed out of maximum four graphical elements with the ability to be freely shaped. This tool enables application of physical laws for the analysis of existing technical systems and also for synthesis of new ones. Procedure of formalising the transition from physical laws to a schema of a future technical system is indicated. Physical laws are used to conceptualize or upgrade existing technical systems where the main focus is on their synthesis.
This paper presents model and application of product function matrix and its requests model. Mode... more This paper presents model and application of product function matrix and its requests model. Model is implemented in developed computer Web application. With connections and winning parameters relation between Blower matrix and Diffuser matrix is presented and achieved. In this way it is possible to generate complete product function structure stored in matrix structure. When complete matrix and function structure is created, it is possible to generate physical (shape) product structure.
Priporočila 7. razvojne skupine za procesno tehnologijo za povečanje konkurenčnosti Slovenije : strateški dokument 7. razvojne skupine za Procesno tehnologijo
Original scientific paper A developed model of the first structural shape of the matrix of produc... more Original scientific paper A developed model of the first structural shape of the matrix of product function and its requests model have been shown in practice. It relates functions of the product and its requests model, and technical systems that solve them. Functions are described by parameters, determined by physical laws. The technical systems and functions are related among themselves through correlations that fill the field of the matrix. The correlations are determined through winning parameters. Winning parameters are determined from the set of parameters of each function that have the greatest importance and influence on a specific function. The model is implemented into a developed prototype computer system. The first structural shape of the product function matrix and its requests model for the stator of the electrical motor of the intake unit have been generated through the prototype computer system. By implementing the product function matrix and its requests model in the process of product conceptual design, it becomes possible for a designer to examine himself by comparing the possibilities of implementation of new ideas with previously built products. Izvornoznanstveni članak U radu je prikazan razvijeni model prvog strukturnog oblika matrice funkcije proizvoda i model njezinih zahtjeva koji dovodi u međusobne odnose funkcije proizvoda i tehničke sustave koji ih rješavaju. Funkcije su opisane parametrima, određenim iz fizikalnih zakona. Tehnički sustavi i funkcije povezani su između sebe preko poveznica koje popunjavaju polja matrice. Poveznice su određene preko pobjednih parametara. Pobjedni parametri se određuju iz skupa parametara svake funkcije te imaju najveći značaj i utjecaj na određenu funkciju. Model je implementiran u razvijeni prototipni računalni sustav, pomoću kojeg je u ovom radu generiran prvi strukturni oblik matrice funkcije proizvoda i njezinih zahtjeva za stator elektromotora usisne jedinice. Primjenom modela matrice funkcije proizvoda i njihovih zahtjeva, u procesu koncipiranja proizvoda, omogućuje se konstruktoru preispitivanje samoga sebe uspoređujući mogućnosti realizacije novih ideja s već prethodno napravljenim proizvodima.
Once a product is developed and its manufacture begins, its level of excellence immediately start... more Once a product is developed and its manufacture begins, its level of excellence immediately starts decreasing due to other competitive products on the market. Its life on the market can be prolonged by continual product improvements. A longer product lifetime also increases its profitability, because the development of a new family of products is associated with considerable costs. The paper presents product re-engineering using an example of a vacuum cleaner motor and its positioning in the product development cycle. The development of vacuum cleaner motors (motor and turbine assembly) is progressing in the direction of increasing the number of revolutions and decreasing their mass and volume. The performed analysis of vacuum cleaner motor construction indicated several possibilities for increasing the number of revolutions. The basic problem concerns the influence of individual components on critical speed. The paper assesses the applicability of individual methods for the analysi...
The results of a numerical simulation of meshing polymer and composite gears are presented in the... more The results of a numerical simulation of meshing polymer and composite gears are presented in the paper. The numerical model used for simulations was built in Ansys Workbench 15.0, using the finite element method to obtain the solution. The results are related to the gear tests, performed by the authors and presented in the literature. A detailed stress and strain analysis of meshing gears is presented. On the basis of which gears of different polymer and composite materials can be rated and appropriate material combinations can be chosen. With the presented numerical model, root and flank stresses in each meshing point along the path of contact can be calculated. Stresses (root and flank) obtained by simulations will be compared with the stresses calculated according to VDI 2736 guideline. The numerical model takes into account friction between the tooth flanks in contact, which significantly contributes to improving the accuracy of the numerical solution. (Less)
Original scientific paper Vortex wake interaction of a rectangular prism is numerically investiga... more Original scientific paper Vortex wake interaction of a rectangular prism is numerically investigated. The wind barrier is accurately geometrically represented with a threedimensional model in the numerical simulation. The barrier model consists of horizontal bars with different inclination angles. The unsteady Reynoldsaveraged Navier-Stokes (URANS) computation is applied because the flow is not statistically stationary. The shear stress transport (SST) k-ω turbulence model is used because it shows good behavior in adverse and separated flows. Experimental study is performed to confirm the numerical data. The aim is to enhance the present level of understanding regarding bluff body wake interference flow and analyze the barrier’s bar inclination effect on the sheltered object. As the bar inclination angle decreases, the bleed flow gets stronger, which results in a smaller reduction of the drag imposed on the sheltered object. The turbulent structures between the barrier and the shelt...
Research in Engineering Design, 2021
The smart factories that are already beginning to appear employ a completely new approach to prod... more The smart factories that are already beginning to appear employ a completely new approach to product creation. Smart products are uniquely identifiable and know both their current status and alternative routes to achieving their target state. Smart factories allow individual customer requirements to be met, meaning that even one-off items can be manufactured profitably. In smart industry, dynamic business and engineering processes enable last-minute changes to design and production, delivering the ability to respond flexibly to disruptions and failures on behalf of suppliers. This paper presents a case study of product development and design process renovation according to changeability paradigm in one-of-a-kind industrial environment. It demonstrates how integration of changeability with agile design strategies crucially contribute to improve the operations of a highly individualized product development business. Successful management of ‘never-ending’ engineering changes appears t...
Mechanism and Machine Theory, 2020
The presented work is focused on the development of a comprehensive thermo-mechanical model for p... more The presented work is focused on the development of a comprehensive thermo-mechanical model for predicting the temperature rise in thermoplastic polymer spur gears with any desired profile geometry while running. The specific constitutional behavior of thermoplastics influences the gear-meshing pattern, which can deviate substantially from ideal gear meshing, as typically exhibited by metal gears in moderate-loading conditions. Taking this aspect into account is of paramount importance if realistic temperature-rise predictions are to be made. The thermal response of the considered gear pair is studied thoroughly from both the analytical and experimental standpoints. Good agreement was found between the results of the model and the experimental measurements performed using a high-speed thermal imaging infrared camera, although it was also observed that the reallife temperature rise can increase noticeably if large geometric tolerance deviations from the ideal profile geometry are present. The presented experimental approach also offers the possibility to observe the temperature rise inside and outside the meshing cycle.